Ischemic Heart Failure

Ischemic heart failure is a clinical condition characterized by left ventricular dysfunction secondary to chronic myocardial ischemia or previous myocardial infarction.
It is one of the leading causes of heart failure with reduced ejection fraction (HFrEF) and is associated with high morbidity and mortality.
The primary risk factor for ischemic heart failure is a previous myocardial infarction, which causes irreversible myocardial necrosis and ventricular remodeling.
Other cardiovascular risk factors, such as hypertension, dyslipidemia, diabetes mellitus, obesity, and smoking, contribute to atherosclerosis progression and reduced myocardial perfusion, accelerating cardiac function decline.

The main pathophysiological mechanisms involved include:

• Myocardial necrosis and fibrosis: Loss of cardiomyocytes leading to reduced contractility.
• Ventricular remodeling: Dilation and alteration of ventricular geometry impairing systolic function.
• Neurohormonal activation: Increased catecholamines, angiotensin II, and aldosterone, worsening myocardial dysfunction.
• Persistent ischemia: Inadequate coronary blood flow to meet myocardial metabolic demands.

Clinical Presentation and Diagnosis

Ischemic heart failure presents with typical symptoms of heart failure. Patients may experience:

• Dyspnea on exertion and orthopnea.
• Peripheral edema and venous congestion.
• Exercise intolerance and fatigue.
• Palpitations and ventricular arrhythmias.
• Angina in cases of ongoing ischemia.

Diagnostic tests include:

• ECG: Signs of previous ischemia (Q waves) or conduction abnormalities.
• Echocardiogram: Assesses ejection fraction, ventricular remodeling, and segmental wall motion abnormalities.
• Cardiac MRI: Identifies areas of myocardial fibrosis and residual viability.
• Myocardial perfusion scintigraphy: Differentiates reversible ischemia from necrotic tissue.
• Coronary angiography: Essential for assessing coronary anatomy and determining revascularization strategies.

Treatment of Ischemic Heart Failure

Treatment aims to improve cardiac function, reduce symptoms, and prevent cardiovascular events.

Lifestyle modifications: A low-sodium diet, controlled physical activity, smoking cessation, and blood pressure management improve prognosis.

Pharmacological therapy:

• ACE inhibitors and ARBs: Reduce afterload and ventricular remodeling.
• Beta-blockers: Improve ventricular function and reduce mortality.
• Aldosterone antagonists: Counteract myocardial fibrosis.
• Diuretics: Control pulmonary and peripheral congestion.
• Anticoagulants: Essential for patients with atrial fibrillation or intracardiac thrombi.

Myocardial revascularization: In patients with significant myocardial ischemia, percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) can improve ventricular function and reduce mortality.

Advanced therapy: In patients with advanced heart failure, additional interventions may be required:

• Implantable cardioverter-defibrillator (ICD): For sudden cardiac death prevention.
• Cardiac resynchronization therapy (CRT): For patients with ventricular dyssynchrony.
• Heart transplantation: In severe cases.

Prognosis and Complications

Ischemic heart failure is a progressive condition with a high risk of refractory heart failure, ventricular arrhythmias, and sudden cardiac death. However, optimized treatment can significantly improve quality of life and survival.

References
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