Arrhythmogenic right ventricular cardiomyopathy

Article written and reviewed by Dr Luca Moretti

Arrhythmogenic right ventricular cardiomyopathy is a myocardial disease in which progressive cardiomyocyte loss and fibrous or fibrofatty replacement predominantly affect the right ventricle, simultaneously creating mechanical failure and electrical instability. The international designation ARVC, from arrhythmogenic right ventricular cardiomyopathy, has largely replaced the historical term dysplasia because the disease is not simply a congenital developmental abnormality but a genetically determined, dynamic process.

ARVC represents the classic right-sided phenotype within the broader spectrum of arrhythmogenic cardiomyopathies. This distinction is clinically decisive: predominance of lesions in the right ventricle does not mean that the left ventricle is always spared, but a left-sided or biventricular form should not automatically be subsumed under historical ARVC. The right-dominant phenotype retains specific criteria, differential diagnosis and prognostic models.

Clinical expression ranges from genetic positivity without demonstrable abnormalities to sudden cardiac death, including premature beats, ventricular tachycardias, syncope and heart failure. In early stages the electrical substrate may already be dangerous while global dimensions and function appear nearly normal; in advanced stages right ventricular dilatation becomes evident and may be associated with left ventricular impairment. Electrical-mechanical dissociation explains why an isolated echocardiogram cannot reassure a person with arrhythmias or a suggestive family history.

There is no biomarker or test capable of confirming the diagnosis on its own. ECG, rhythm monitoring, echocardiography, cardiac magnetic resonance, family history, genetics and, in selected cases, histology must be integrated through shared criteria and interpreted in relation to age, sports activity and pre-test probability. Multimodal diagnosis avoids both missing early forms and labeling normal variants of the right ventricle as pathologic.

The purpose of diagnosis is not to assign a name to an image, but to prevent events in a familial and modifiable disease. Restriction of intense exercise, risk stratification, a defibrillator when appropriate, control of tachycardias and surveillance of relatives can change the course. Longitudinal care is essential because phenotype, scar and risk evolve over time.

Pathology, genetics and arrhythmogenic mechanisms

The characteristic pathologic finding consists of myocyte loss with scar replacement, often accompanied by adipose tissue, distributed heterogeneously in the right ventricular free wall. The process tends to progress from the epicardium toward the endocardium and may leave islands of viable myocardium separated by fibrosis, an ideal configuration for slow conduction and re-entry. The fibrofatty scar is therefore both a structural lesion and the substrate for tachycardias.

The concept of the triangle of dysplasia, formed by the right ventricular inflow tract, outflow tract and apex, describes many advanced forms well but not the entire spectrum. Pathologic and imaging studies show broader and more variable distributions, with frequent inferior, subtricuspid and posterolateral involvement and possible extension to the left ventricle. The triangular model therefore should not be used to exclude disease that does not follow that classic geometry.

Most familial forms follow autosomal dominant inheritance with age-dependent penetrance and variable expressivity. A clinically silent parent may transmit the variant to a child with manifest disease, while carrier siblings may differ in age at onset, arrhythmic burden and degree of dysfunction. Incomplete penetrance makes a family history limited to already known diagnoses insufficient.

PKP2, which encodes plakophilin-2, is the gene most frequently involved in the classic right-sided phenotype; DSG2, DSC2, DSP and JUP encode other desmosomal components. The desmosome provides mechanical adhesion between cardiomyocytes and participates in intracellular signaling, so its disruption may impair tissue integrity, electrical junctions and the response to stress. Desmosomal biology links mechanical wall load to electrical vulnerability.

Variants in TMEM43 and a more limited number of non-desmosomal genes may produce right-sided or mixed arrhythmogenic phenotypes, but the strength of gene-disease association must be critically assessed. Some genes historically included in panels have limited evidence, whereas DSP and PLN often tend toward left-sided or biventricular manifestations requiring broader classification. A curated genetic panel reduces uncertain variants and false causal attributions.

Recessive forms clarify the link between the heart and tissues exposed to stress. Naxos disease caused by JUP combines arrhythmogenic cardiomyopathy, woolly hair and palmoplantar keratoderma, whereas some biallelic DSP variants cause cardiocutaneous syndromes. Cutaneous signs may precede the cardiac phenotype and guide genetics, pediatric surveillance and reproductive counseling.

Endurance exercise is not the sole cause of genetic ARVC, but acts as a powerful modifier of penetrance and progression. Repeated increases in volume, pressure and wall stress on the right ventricle promote cell injury in tissue with vulnerable adhesion; studies in desmosomal variant carriers show dose-dependent associations with phenotypic expression and arrhythmias. The gene-exercise interaction is among the strongest evidence for environmental prevention in inherited cardiomyopathies.

Phases of acute injury with chest pain and troponin elevation may occur, especially in certain genotypes, but are more typical of left-involving forms such as DSP cardiomyopathy. In classic ARVC, inflammation and infiltrates may be present in the pathologic lesion without automatically demonstrating primary myocarditis. The inflammatory component must be interpreted together with scar distribution, genotype and course, avoiding a false dichotomy between genetic disease and inflammation.

Clinical evolution, symptoms and arrhythmias

The course is often described as a sequence of concealed phase, electrical phase, manifest right-sided structural disease and biventricular stage. This sequence is useful but not mandatory: some patients remain minimally symptomatic for decades, others present with cardiac arrest, and still others progressively develop heart failure. Clinical phases are possible trajectories, not inevitable stages of equal duration.

The disease most often manifests from late adolescence into adulthood, whereas a complete phenotype before puberty is less common. Palpitations, presyncope or syncope during exercise, awareness of irregular beats and reduced exercise tolerance require particular attention, especially when there is a family history of sudden death at a young age. Exertional syncope should not be considered vasovagal without adequate arrhythmic assessment.

Arrhythmias originate from the right ventricle and therefore generally have left bundle branch block morphology. A superior axis suggests an inferior or apical origin and is more specific for an arrhythmogenic scar substrate, whereas an outflow-tract morphology with inferior axis may overlap with common idiopathic ectopy. Tachycardia morphology localizes the circuit and has diagnostic value beyond simply counting episodes.

Frequent premature ventricular beats and nonsustained tachycardias may precede major arrhythmias. The total number over 24 hours is informative, but so are complexity, multiple morphologies, relationship to exertion and change over time; a single Holter recording below a threshold does not eliminate intermittent disease. The ectopic burden acquires meaning when linked to its anatomic origin and the rest of the phenotype.

Sustained ventricular tachycardia may be relatively well tolerated when slow and monomorphic or may cause syncope, shock or degeneration into ventricular fibrillation. A first hemodynamically stable episode is not benign because it documents a substrate capable of recurrence, whereas cardiac arrest identifies very high secondary risk. The arrhythmic presentation determines the urgency of defibrillator protection and cannot be replaced by a score.

As myocyte loss advances, right ventricular dilatation, functional tricuspid regurgitation, elevated venous pressures, hepatomegaly, ascites and edema develop. In some patients, left ventricular function declines in parallel or later, transforming the picture into biventricular failure. Right-sided heart failure is less common than an arrhythmic presentation but strongly affects prognosis, drug tolerance and transplant candidacy.

Sudden death may be the first manifestation, especially during intense activity, but risk is not uniform among all carriers. Presymptomatic diagnosis, exercise reduction and surveillance have changed the natural history observed in older autopsy series. Concealed risk justifies family screening, not indiscriminate implantation of devices in every genetically positive person.

Diagnostic criteria: Task Force, Padua and European consensus

The revised 2010 International Task Force Criteria were developed specifically for classic ARVC. They organize findings into six domains: morphofunctional abnormalities, histologic characterization, repolarization, depolarization, arrhythmias, and family or genetic history, assigning major or minor weight to each element. The 2010 criteria have high specificity for the right-sided phenotype but were not designed to adequately recognize left-sided variants of the arrhythmogenic spectrum.

Under that system, the diagnosis is definite with a combination of two major criteria, or one major and two minor criteria, or four minor criteria from different categories. One major and one minor, or three minor criteria from different categories, constitutes a borderline diagnosis; one major or two minor criteria from different categories constitute a possible diagnosis. Combination across domains prevents a single nonspecific abnormality from governing the judgment.

In the 2010 morphofunctional domain, a regional right ventricular abnormality must be associated with quantitatively defined dilatation or dysfunction. On echocardiography, the major criterion combines regional akinesia, dyskinesia or aneurysm with an end-diastolic outflow tract diameter of at least 32 mm in the parasternal long-axis view, at least 36 mm in the short-axis view, or fractional area change no greater than 33%; the corresponding indexed thresholds are 19 and 21 mm/m². The minor criterion requires the same regional abnormality with diameters respectively from 29 to less than 32 mm or from 32 to less than 36 mm, indexed values from 16 to less than 19 or from 18 to less than 21 mm/m², or fractional area change greater than 33% but no greater than 40%. The regional-quantitative requirement increases specificity compared with visual impression alone.

On CMR, the 2010 major criterion combines regional akinesia, dyskinesia or dyssynchronous contraction with an indexed right ventricular end-diastolic volume of at least 110 mL/m² in men or 100 mL/m² in women, or with an ejection fraction no greater than 40%. The minor criterion associates the regional abnormality with a volume from 100 to less than 110 mL/m² in men or from 90 to less than 100 mL/m² in women, or with an ejection fraction greater than 40% but no greater than 45%; angiography may directly document akinesia, dyskinesia or aneurysm. These historical thresholds must be applied with correct technique and not replaced by qualitative estimates.

Repolarization abnormalities include as a major criterion T-wave inversion from V1 to V3 or beyond after age 14, in the absence of complete right bundle branch block. Inversions limited to V1-V2, extending to lateral leads, or present from V1 to V4 with complete block carry different minor weight depending on context. Negative T waves are sensitive in manifest forms, but age, sex, electrode position and normal variants influence their specificity.

The epsilon wave, a small reproducible potential between the end of the QRS and the onset of the T wave in the right precordial leads, was a major criterion in 2010. Its sensitivity is low and interobserver agreement is limited, especially in the presence of artifacts, filters or terminal QRS fragmentation; subsequent criteria therefore reduced its weight. The epsilon wave is a sign of delayed activation, not a requirement or a stand-alone proof.

The 2010 depolarization criteria also include late potentials on signal-averaged ECG and terminal activation duration of at least 55 ms in V1-V3, in the absence of complete block. These indices seek slowed conduction in the right ventricle but depend on recording quality and definition of QRS termination. Terminal activation delay must be measured, not inferred from a noisy tracing.

The arrhythmic domain assigns greater specificity to nonsustained or sustained tachycardia with left bundle branch block morphology and a superior axis, whereas an outflow-tract morphology with an inferior axis has minor weight. More than 500 premature ventricular beats over 24 hours also constitute a minor criterion in the 2010 system. The geography of ectopy distinguishes, as far as possible, a right inferior scar from idiopathic outflow tract tachycardia.

The histologic domain requires fibrous replacement of the right ventricular free wall, with or without adipose tissue, documented in at least one sample. The major criterion corresponds to less than 60% residual myocytes on morphometric analysis, or less than 50% when estimated; the minor criterion identifies a residual proportion between 60% and 75% by morphometry, or between 50% and 65% by estimation. These histologic thresholds do not eliminate sampling error in a heterogeneous disease and do not justify routine biopsy.

In the family and genetic domain, major criteria include ARVC confirmed according to current criteria in a first-degree relative, pathologic demonstration of disease in a first-degree relative, or identification in the proband of a pathogenic ARVC-associated variant. Minor criteria include an unverifiable history of ARVC in a first-degree relative, sudden death before age 35 suspicious for this disease in a first-degree relative, or confirmed ARVC in a second-degree relative. A variant of uncertain significance does not fulfill the genetic criterion and cannot be used for predictive cascade screening.

The 2020 Padua criteria broadened the diagnostic framework to the entire arrhythmogenic spectrum and formally introduced scar characterization with late gadolinium enhancement. For the right-sided phenotype, they distinguish isolated regional abnormalities from abnormalities associated with global dilatation or dysfunction, consider transmural right ventricular fibrosis on CMR, and reduce the weight of poorly reproducible signs such as the epsilon wave. The Padua criteria do not erase the historical validity of the TFC for ARVC but correct their phenotypic and tissue limitations.

The European Task Force consensus published in 2024 refined the Padua criteria by proposing a diagnostic framework for ARVC, the biventricular form and ALVC, with greater weight given to CMR and nonischemic scar. This system does not coincide with the 2023 ESC morphofunctional classification: the ESC retains ARVC as a predominantly right-sided phenotype and places many nondilated left-sided presentations within NDLVC, without treating arrhythmogenic cardiomyopathy as an autonomous umbrella subtype. ALVC and NDLVC are therefore not interchangeable terms. In the European Task Force system, ARVC diagnosis presupposes at least one right-sided morphofunctional or structural criterion and the absence of analogous left-sided criteria; isolated genetics or arrhythmia do not define manifest cardiomyopathy. The current diagnostic framework should be stated in the report because different systems do not perfectly overlap.

ECG, imaging, genetics and biopsy

The standard ECG retains a central role because it detects diffuse repolarization abnormalities and signs of delayed conduction. It should be recorded with correct precordial lead placement, compared with previous tracings and interpreted with knowledge of bundle branch blocks, age and training level. Electrocardiographic evolution may be more informative than an isolated snapshot and justifies serial assessments in relatives.

Ambulatory monitoring quantifies premature beats, nonsustained tachycardias and their relationship to symptoms, while multilead recordings help define morphology. Longer monitoring increases yield when episodes are sporadic, but the values obtained are not directly equivalent to the historical threshold developed from 24-hour recordings. Rhythm documentation should preserve diagnostic tracings, not merely the software's automated count.

Exercise testing may provoke ectopy and clarify symptoms, functional capacity and chronotropic response, but should not become repeated maximal exposure without reason in a person already at risk. A negative test does not exclude ARVC, and induced tachycardia should be interpreted according to morphology and context. Controlled provocation has a specific diagnostic purpose and does not replace monitoring in real life.

Echocardiography assesses outflow tract diameters, end-diastolic and end-systolic areas, fractional area change, regional abnormalities, tricuspid function and hemodynamic consequences. The retrosternal, geometrically complex right ventricle is vulnerable to foreshortening and oblique planes that simulate dilatation or abnormal motion. Echocardiographic technique should follow standardized acquisitions and compare findings with body size and training load.

TAPSE and annular systolic velocity mainly describe longitudinal function and may remain normal in the presence of regional disease. Three-dimensional echocardiography and free-wall strain may identify early abnormalities and mechanical dispersion, but are not universally standardized stand-alone diagnostic criteria. Regional deformation complements, without replacing, validated measurements and multimodal judgment.

Cardiac magnetic resonance is the most comprehensive method for volumes, ejection fraction, regional wall motion and left ventricular involvement. Segmentation of the thin right ventricle requires expertise because trabeculations, the moderator band and the valve plane materially affect volumes; apparent dyskinesia near the sternal insertion may also be artifactual. Expert CMR interpretation is essential to avoid overdiagnosis, especially in athletes.

Late gadolinium enhancement demonstrates scar and has acquired a formal role in the most recent criteria, but the thin right ventricular wall makes its detection more difficult than in the left ventricle. A transmural stria-pattern reproduced in orthogonal planes and coherent with regional abnormalities is more convincing than an isolated signal at the blood pool margin. Right ventricular LGE must be distinguished from partial-volume effects, epicardial fat and motion artifact.

Demonstration of intramyocardial fat by CMR or CT is not sufficient because epicardial adiposity and age- or obesity-related infiltration may be normal. For the same reason, the term fibrofatty does not justify a radiologic diagnosis based on fat. Arrhythmogenic fibrosis, associated with dysfunction and electrical signs, has greater biologic significance.

Genetic testing is indicated in a proband with a convincing phenotype and is accompanied by pre- and post-test counseling. A pathogenic or likely pathogenic variant in a validated gene can support the diagnosis and enables cascade testing, whereas a variant of uncertain significance should not guide an ICD, diagnosis in relatives or discharge from follow-up. The causal variant is interpreted through frequency, mechanism, segregation and phenotypic concordance.

Endomyocardial biopsy is not routine because the disease is heterogeneous, septal sampling may not reach the involved free wall and a thinned right ventricle carries a perforation risk. It may be useful when sarcoidosis, myocarditis or another treatable diagnosis remains plausible, potentially with electroanatomic or imaging guidance. Selective biopsy answers a concrete differential question and is not used to compensate for equivocal imaging.

Differential diagnosis and prevention of overdiagnosis

Idiopathic right ventricular outflow tract tachycardia often presents with premature beats or tachycardia with left bundle branch block morphology and an inferior axis, but generally is not associated with scar, progressive regional dysfunction, extensive T-wave inversion or causal family history. It may nonetheless produce a high ectopic burden and even arrhythmia-induced cardiomyopathy. Outflow tract tachycardia is distinguished through detailed morphology, imaging and response to ablation, not by the general axis alone.

The endurance athlete's heart may show proportionate right ventricular dilatation, increased volumes and ECG changes that partially overlap with historical criteria. In athletic physiology, global function is preserved, enlargement tends to be balanced between chambers, and convincing regional scar and complex multifocal arrhythmias are absent. Athletic remodeling requires specific reference values and cannot be judged using non-contextualized cutoffs.

Cardiac sarcoidosis and myocarditis can create scar, conduction block, ventricular tachycardia and regional right ventricular abnormalities. Atrioventricular block, inflammatory uptake, septal or multifocal LGE distribution and extracardiac manifestations favor alternative diagnoses, but no sign is absolute. Inflammatory disease should be actively sought when the picture is atypical because immunosuppression and prognosis differ.

Pressure overload from pulmonary hypertension and volume overload from an atrial septal defect or anomalous pulmonary venous return dilate the right ventricle without constituting ARVC. Doppler echocardiography, MR angiography or CT clarify pressures, shunts and vascular anatomy. Hemodynamic loading must be excluded before attributing dilatation and tricuspid regurgitation to a primary cardiomyopathy.

Ebstein anomaly, double-chambered right ventricle, repaired congenital heart disease and the rare Uhl anomaly alter right ventricular morphology and function. Surgical history, tricuspid leaflet insertion and segmental anatomy often make the cause evident, but mild forms may be missed in a cursory examination. Congenital morphology takes precedence over applying any cardiomyopathy score.

Right ventricular infarction, Chagas disease in relevant epidemiologic settings, toxic injury and neuromuscular cardiomyopathies may mimic parts of the phenotype. Advanced DCM also causes secondary right ventricular dysfunction, but the temporal relationship, scar and ventricular predominance differ. Etiologic diagnosis requires exposures, geographic origin, coronary assessment and systemic evaluation, not only classification by shape.

Overdiagnosis leads to exclusion from sports, family anxiety, inappropriate cascade genetic testing and sometimes an unnecessary ICD; underdiagnosis instead exposes patients to preventable death. In borderline cases, it is preferable to document uncertainty, reassess over time and obtain review of imaging and tracings at an expert center. Probabilistic judgment is safer than forcing equivocal findings into a binary diagnosis.

Risk stratification and prognosis

A diagnosis of ARVC does not imply a uniform risk of sudden death. Previous cardiac arrest, ventricular fibrillation or hemodynamically unstable sustained tachycardia identifies secondary prevention, in which the probability of recurrence is substantial. A major arrhythmic history remains more informative than any isolated marker.

For primary prevention, likely arrhythmic syncope, nonsustained tachycardia, premature ventricular beat frequency, extent of negative T waves, right and left ventricular function, sex, age and longitudinal course are integrated. A dramatic family history warrants attention but does not automatically transfer the same risk to an individual because of intrafamilial variability. Individual estimation should separate robust prognostic evidence from emotionally understandable impressions.

The ARVC Risk Calculator estimates the five-year risk of a first sustained ventricular arrhythmia in patients with a definite diagnosis according to the 2010 criteria and no previous sustained event. It uses age, sex, recent syncope, nonsustained tachycardia, premature ventricular beat burden, number of leads with T-wave inversion and right ventricular ejection fraction. The ARVC calculator supports shared ICD decision-making but does not directly measure every form of sudden death and should not be extrapolated to phenotypes or populations not represented.

External validations have confirmed clinically useful discrimination while also showing possible differences in calibration and overestimation in some subgroups. The model is particularly well studied in classic ARVC and appears to perform better in PKP2-related forms than in some left-sided arrhythmogenic cardiomyopathies or different genotypes. Domain validity prevents applying the number to every carrier of a desmosomal gene.

Electrophysiologic study with programmed ventricular stimulation may add information in selected cases, but sensitivity and predictive value depend on the population, protocol and pre-test risk. An inducible result does not replace clinical markers, whereas noninducibility does not guarantee absolute protection. Programmed stimulation is a complementary tool, especially when the device decision remains uncertain.

Structural progression increases risk because it expands scar and reduces hemodynamic reserve, but severe arrhythmias may occur before marked dysfunction. For this reason, ejection-fraction thresholds used in dilated cardiomyopathy are not sufficient in ARVC. Right ventricular function must be interpreted together with symptoms, rhythm and serial trajectory.

The prognosis of diagnosed and treated patients is better than suggested by early sudden-death series. Registries show a high burden of sustained arrhythmias in probands, but relatively limited cardiac mortality and need for transplantation when protection and follow-up are appropriate. Contemporary prognosis therefore also depends on the effectiveness of prevention, creating differences from untreated natural history.

Follow-up reassesses symptoms, ECG, arrhythmic burden, function, scar, therapies and device status at a frequency adapted to the disease phase. A long stable period does not eliminate predisposition, whereas increasing ectopy, new T-wave inversions or worsening function may signal progression. Dynamic stratification recognizes that the correct decision today may need revision tomorrow.

Prevention, ICD, drugs and ablation

Reducing high-intensity exercise is a causal therapy directed at the main known modifier. Competitive sports and intense endurance exercise are contraindicated in manifest disease, and residual activity is prescribed individually according to arrhythmias, function, symptoms and device status. Intensity restriction reduces risk but does not replace an ICD when an independent indication exists.

An implantable defibrillator is recommended after cardiac arrest or high-risk sustained ventricular tachycardia and is discussed for primary prevention when the probability of events justifies cumulative complications. In a young person, decades of leads, infections, replacements, inappropriate shocks and psychological impact carry particular weight. The ICD decision balances arrhythmic risk, life expectancy, anatomy, activity and informed preferences.

The choice between a transvenous and subcutaneous system depends on the need for antitachycardia pacing, bradycardia, tachycardia morphology and anatomy. Antitachycardia pacing can effectively terminate many relatively slow monomorphic tachycardias, an advantage a subcutaneous system does not offer; on the other hand, avoiding endovascular leads reduces specific long-term complications. Device configuration should anticipate the likely type of arrhythmia rather than follow a generic preference.

ICD programming seeks to prevent avoidable shocks without delaying treatment of dangerous arrhythmias. Detection zones, duration, discriminators and pacing sequences are adapted to documented tachycardia and hemodynamic tolerance; remote monitoring facilitates early recognition of recurrences and technical problems. Device therapy continues after implantation and requires specific electrophysiologic expertise.

Beta-blockers limit adrenergic stimulation and are frequently used, especially in the presence of arrhythmias, an ICD or dysfunction. Sotalol and amiodarone may reduce recurrences in selected patients, but incomplete efficacy and toxicity prevent them from being considered substitutes for a defibrillator. Antiarrhythmic therapy aims to reduce symptoms and device therapies, not to eliminate the substrate.

Flecainide combined with beta-blockade, and not with other antiarrhythmics, may be considered at expert centers for persistent or refractory arrhythmias in selected patients with preserved right and left ventricular function and ICD protection. This is a strategy to reduce arrhythmic burden, not an alternative to the defibrillator; it requires monitoring of QRS, renal function, interactions and proarrhythmic potential. Drug selection depends on arrhythmia type and the individual's safety profile.

Catheter ablation is indicated for recurrent tachycardia, electrical storm or repeated ICD therapies despite drugs and appropriate programming. The substrate often begins epicardially, so an endocardial-only procedure may not reach critical channels; combined endocardial and epicardial mapping improves control in many cases. Substrate ablation should be performed at centers experienced in pericardial access and its complications.

Elimination of inducible tachycardia after ablation does not equal cure. New scarred areas may develop and long-term recurrences remain possible, making monitoring and often continued ICD therapy necessary. Recurrence control is a realistic goal, distinct from definitive prevention of sudden death.

When ventricular failure develops, diuretics control congestion and heart-failure therapy is applied according to left ventricular function, blood pressure and tolerance, despite the absence of large trials dedicated to ARVC. Atrial arrhythmias, intracavitary thrombi and tricuspid regurgitation are treated according to specific indications. Hemodynamic management must avoid both undertreatment of heart failure and poorly tolerated drugs in a preload-dependent circulation.

Heart transplantation is considered for refractory end-stage heart failure or uncontrollable arrhythmias despite drugs, ablation and device therapy. Severe right-sided involvement may limit some mechanical assist strategies designed only for the left ventricle and makes timely referral to a transplant center crucial. Advanced disease requires planning before cachexia or hepatic or renal injury reduces options.

Family members, physical activity and life across different ages

Family assessment begins with a pedigree of at least three generations documenting syncope, arrhythmias, cardiomyopathy, transplantation, sudden death and extracardiac diagnoses. Autopsy reports and tracings from deceased relatives can transform a vague history into useful evidence. A verified family history guides both genetic probability and the age at which surveillance should begin.

When the proband has a coherent pathogenic or likely pathogenic variant, targeted testing identifies relatives who inherited it. A non-carrier can generally be discharged from specific follow-up if the variant convincingly explains the family, whereas a VUS does not allow this separation. Cascade genetic testing is more informative and less ambiguous than repeating broad panels in every relative.

First-degree relatives at risk are assessed with history, examination, ECG, rhythm monitoring and imaging at intervals adapted to age, gene and family history, often every one to three years from preadolescence. Very early or malignant onset in the family justifies earlier surveillance, whereas new symptoms require immediate reassessment regardless of the calendar. Serial screening is necessary because initial normality does not exclude later penetrance.

A genotype-positive, phenotype-negative carrier is not ill in the same sense as the proband, but has susceptibility that modifies exercise and surveillance. They do not automatically receive drugs or an ICD; instead, they are informed about symptoms, protected from intense activity and followed to recognize electrical or structural onset. The prephenotypic phase requires proportionate prevention without excessive medicalization.

Health-promoting physical activity is not the same as competitive sport. In patients with manifest ARVC, regular low-intensity recreational activities compatible with individual capacity are favored, while exercise to exhaustion, competition, dehydration and environments in which syncope would be catastrophic are avoided. The exercise prescription should be explicit because generic advice to exercise moderately is interpreted in very different ways.

Pregnancy is often tolerated in clinically stable women, but increased volume, heart rate and hemodynamic demands require preconception assessment and follow-up with a cardiology-obstetric team. Biventricular dysfunction, previous arrhythmias and drug therapy modify maternal risk and delivery management; cesarean delivery is not mandated by the diagnosis alone. The preconception pathway distinguishes maternal cardiac risk from genetic probability for the child.

In autosomal dominant forms, each child generally has a 50% probability of inheriting the variant, but not a 50% probability of developing the same phenotype or severity. Reproductive counseling, prenatal diagnosis and preimplantation testing are discussed non-directively when the familial variant is known. Hereditary risk should be communicated by separating transmission, penetrance and expressivity.

Driving restrictions, safety-sensitive occupations and solitary activities depend on syncope, recent arrhythmias, ICD therapies and national regulations. Shock-related anxiety, fear for children and loss of athletic identity are real clinical consequences and may require psychological support. Quality of life is not ancillary to prevention because it influences adherence, symptom perception and device decisions.

ARVC ultimately requires continuity among clinical cardiology, imaging, electrophysiology and genetics. Rigorous diagnosis avoids labels based on a single finding, while structured follow-up detects the transition from susceptibility to disease and from stability to high risk. Integrated care transforms a potentially lethal cardiomyopathy into an often controllable condition, without eliminating its progressive nature.