Amyloid and sarcoid affect the heart in what manner?

Amyloid and sarcoidosis primarily affect the heart through the mechanism of restrictive cardiomyopathy. In these conditions, abnormal protein deposition or granulomatous inflammation leads to thickening of the myocardial interstitium, which subsequently restricts the heart's ability to fill properly during diastole.

In amyloidosis, the deposition of misfolded proteins in the cardiac tissues leads to stiffening of the myocardium, which results in impaired diastolic filling and elevated filling pressures. This often manifests as heart failure with preserved ejection fraction and can progress to more severe heart failure if untreated.

Similarly, in sarcoidosis, the presence of inflammatory granulomas in the myocardium also causes restriction of the heart's capacity to fill properly. This condition can lead to arrhythmias and heart block due to the disruption of the normal electrical conduction system as well.

Recognizing that both amyloid and sarcoid primarily impact the heart's filling dynamics helps in accurately diagnosing and managing these conditions. Other heart conditions, such as dilated cardiomyopathies or ischemic heart diseases, involve different pathophysiological processes and result in different clinical presentations, distinguishing them from the restrictive pattern seen with amyloid and sarcoidosis.