Paradoxic improvement in regional wall motion during high-dose dobutamine stress echocardiography. A marker for hibernating myocardium?

Dobutamine stress echocardiography detects myocardial ischemia by inducing regional left ventricular systolic dysfunction. Augmentation of wall motion in hypokinetic segments has also been noted with low-dose dobutamine, suggesting myocardial viability. We report a case of regional ventricular improvement during high-dose dobutamine therapy, which may represent relief from myocardial hibernation or changes in regional loading conditions.

Aortic valve stenosis. Management in children and adults.

Aortic valve stenosis may be congenital or acquired. Medical management includes advice to avoid heavy physical effort, prevention of infective endocarditis, use of digitalis and diuretics for cardiac failure, and preservation of atrial systole. When operation is necessary, open aortic valve commissurotomy is preferred in children and replacement of the valve is preferred in adults.

Patent foramen ovale associated with platypnea and orthodeoxia.

A case of positionally symptomatic right-to-left shunting across a patent foramen ovale with both platypnea and orthodeoxia despite normal pulmonary arterial pressures and normal right ventricular function is documented. When the patient was in a supine position, the calculated right-to-left shunt was 12.8 percent, and when seated 25 percent.

Planar positron imaging of rubidium-82 for myocardial infarction: a comparison with thallium-201 and regional wall motion.

Rubidium-82 (Rb-82) is a generator-produced, short half-life (76 seconds) positron emitting potassium analog. Using a mobile gamma camera equipped with a rotating tungsten collimator and high-energy shielding, we examined the use of Rb-82 in the coronary care unit and clinical laboratory for detection of perfusion defects due to myocardial infarction. We studied 31 subjects, 10 patients with acute myocardial infarction, 12 with remote myocardial infarction, and nine controls.