In patients with syncope and ischemic cardiomyopathy, which is the most common cause of syncope?

In patients with ischemic cardiomyopathy, ventricular tachycardia is the most common cause of syncope due to the heart's decreased ability to effectively pump blood. Ischemic cardiomyopathy often results from significant coronary artery disease, where reduced blood flow to the myocardium causes myocardial damage and subsequent electrical instability. This can lead to sustained or nonsustained ventricular tachycardia, which can compromise cardiac output dramatically due to the rapid heart rate, resulting in decreased perfusion to the brain and thus causing syncope.

In these patients, the structural and electrical abnormalities present owing to ischemic damage significantly predispose them to arrhythmias such as ventricular tachycardia. The presence of ischemic injury alters the normal conduction pathways in the heart, increasing the likelihood of arrhythmias that can precipitate loss of consciousness.

Other factors such as vasovagal responses, aortic stenosis, and electrolyte imbalances can cause syncope as well, but they are less common in the context of patients with ischemic cardiomyopathy. Vasovagal syncope typically arises from a reflex response to stress or pain and is more commonly observed in younger patients or in absence of structural heart disease. Aortic stenosis can lead to syncope