Heart Failure And Pathological Features Of Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is primarily characterized by significant ventricular chamber dilation, which is often visible to the naked eye. The ventricular walls typically become thinner, and myocardial fibrosis or scarring is commonly observed. Intracardiac thrombi may also be present, particularly in the areas where blood flow is sluggish. The valves and coronary arteries, however, usually remain structurally unchanged.

Microscopic Characteristics

Under microscopic examination, the myocardium often displays nonspecific cardiomyocyte hypertrophy and degeneration. A key feature is the presence of varying degrees of interstitial fibrosis, which may coexist with other pathological changes. These histological findings reflect the progressive nature of the disease and the heart's response to chronic stress and dysfunction.

Disease Progression And Symptoms

The onset of dilated cardiomyopathy is often insidious, with patients experiencing no noticeable symptoms in the early stages. As the condition progresses, signs of congestive heart failure begin to emerge. These may include palpitations, shortness of breath, fatigue, and chest discomfort. In more advanced cases, patients may develop orthopnea (difficulty breathing while lying flat), peripheral edema, and hepatomegaly due to fluid retention.

Potential Complications

Complications associated with DCM can be severe and life-threatening. These include systemic embolism due to intracardiac clot formation, arrhythmias that may lead to sudden cardiac death, and progressive heart failure. The risk of sudden cardiac arrest is notably higher in patients with significant left ventricular dysfunction.

Clinical Diagnosis

Physical examination often reveals cardiomegaly—an enlarged heart detected through imaging or physical signs. Additionally, a third or fourth heart sound (S3 or S4 gallop) is frequently audible during auscultation, indicating impaired ventricular filling and diastolic dysfunction.