Complications of Ischemic Heart Disease

Ischemic heart disease can lead to a series of acute and chronic complications, significantly impacting patient prognosis and quality of life.
These complications primarily arise from myocardial damage due to reduced coronary blood flow and the consequent inflammatory and fibrotic response.

Acute Complications

Acute complications occur in the early stages of an ischemic event and require immediate treatment to prevent fatal outcomes.

Malignant Arrhythmias

Myocardial ischemia alters the membrane potential of cardiac cells, favoring the establishment of reentry circuits and the onset of ventricular arrhythmias.
ATP depletion impairs ion channel function, predisposing to electrical instability. As a result, the following rhythm disturbances may occur:

Ventricular tachycardia and fibrillation: the primary cause of sudden cardiac arrest during the acute phase of myocardial infarction.
Bradyarrhythmias: atrioventricular block and sinoatrial node dysfunction, especially in inferior infarctions.

Cardiogenic Shock

Extensive myocardial necrosis drastically reduces the left ventricle's contractile capacity, leading to a drop in cardiac output.
Systemic hypoperfusion activates compensatory adrenergic mechanisms, which, however, increase oxygen consumption and worsen hemodynamic status.
The typical clinical manifestations of cardiogenic shock include:

Severe systemic hypoperfusion with hypotension and reduced organ perfusion.
Oliguria and altered mental status due to inadequate renal and cerebral perfusion.
High mortality without timely intervention with inotropic agents and mechanical support.

Free Wall Rupture and Ventricular Septal Rupture

Transmural infarction, with extensive myocardial necrosis, compromises the structural integrity of the heart. The lack of effective extracellular matrix repair predisposes to ventricular wall or septal rupture.
These structural complications result in:

Free wall rupture: leads to cardiac tamponade with hemodynamic collapse.
Ventricular septal rupture: causes a left-to-right shunt with acute heart failure.

Acute Valvular Insufficiency

Ischemia can impair the function of the papillary muscles, leading to acute mitral valve incompetence.
Acute regurgitation results in a sudden volume overload of the left ventricle, causing rapid hemodynamic deterioration.
This condition manifests with:

Acute pulmonary edema due to increased left atrial pressure.
Reduced cardiac output with systemic hypoperfusion.
Possible indication for urgent surgical intervention.

Chronic Complications

Following an acute ischemic event, long-term complications may develop, impairing cardiac function.

Chronic Heart Failure

The loss of viable myocardial tissue reduces ejection fraction, leading to pulmonary venous hypertension and unfavorable ventricular remodeling.
Chronic neurohormonal activation (renin-angiotensin-aldosterone and sympathetic systems) accelerates heart failure progression.
The main signs of chronic heart failure include:

Exertional dyspnea and reduced exercise tolerance.
Peripheral edema and pulmonary congestion.
Need for therapy with ACE inhibitors, beta-blockers, and diuretics.

Ventricular Aneurysm

Post-infarction scarring can lead to the formation of a segmental dyskinetic area, with progressive dilation and loss of contractile function.
The main consequences of this condition include:

Reduced ejection fraction with heart failure symptoms.
Risk of thromboembolism due to blood stasis in the ventricular cavity.
Possible surgical indication in high-embolism-risk cases.

Dressler's Syndrome

This is a post-infarction autoimmune reaction in which myocardial antigens released by necrosis trigger an inflammatory pericardial response.
The typical symptoms of Dressler’s syndrome include:

Post-infarction pericarditis with chest pain and fever.
Pericardial effusion visible on echocardiography.
Response to NSAIDs and colchicine.

Conclusion

The complications of ischemic heart disease require careful management to reduce mortality and improve patient quality of life. A multidisciplinary approach involving cardiologists, cardiovascular surgeons, and intensive care specialists is essential to optimize prognosis.

References

Steg PG, et al. Management of acute coronary syndromes in emergency settings. European Heart Journal. 2023;44(4):1256-1272.
Ibanez B, et al. 2023 ESC Guidelines for the management of acute coronary syndromes. European Heart Journal. 2023;44(35):2999-3104.
Bhatt DL, et al. Long-term outcomes in patients with post-myocardial infarction complications. J Am Coll Cardiol. 2022;79(17):1852-1867.
Granger CB, et al. Cardiogenic shock in acute myocardial infarction. NEJM. 2020;382(3):271-282.
Tamis-Holland JE, et al. Management of mechanical complications of myocardial infarction. J Am Coll Cardiol. 2019;74(22):2791-2802.