Globular heart
Globular heart from a patient with sickle cell anemia!! This very large heart has a globoid shape because all of the chambers are dilated. It felt very flabby, and the myocardium was poorly contractile. This is an example of a cardiomyopathy. This term is used to denote a disease where the heart muscle (myocardium) becomes weak and unable to contract with sufficient force (decreased contractility leading to a decreased stroke volume) to provide adequate perfusion (reduced cardiac output) for the cells of the body, but there is no specific histologic finding. Dilated cardiomyopathy is a progressive disease of heart muscle that is characterized by ventricular chamber enlargement and contractile systolic dysfunction with normal wall thickness. The right ventricle may also be dilated and dysfunctional. Patients experience fatigue, dyspnea on exertion, shortness of breath, cough, noctural dyspnea (at night) and orthopnea (dyspnea when lying flat). Diagnosis is made by echocardiogram, which typically shows dilated ventricles with diffuse hypokinesia resulting in a low ejection fraction (I.e. systolic dysfunction). Treatment is largely supportive, and mainly involves the management of symptoms caused by congestive heart failure with ACE inhibitors, beta blockers, angiotensin II receptor blockers and nitrates. Cardiac transplantation is an option for patients with severe heart failure, and a left ventricular assist device, or LVAD, may help to bridge a patient while awaiting transplantation.
Hemodynamic stimuli&nonhemodynamic stimuli
