Myocardial Oxygen Consumption During Ventricular Contraction and Relaxation

Myocardial Oxygen Consumption during Ventricular Contraction and Relaxation.

• As early as 1915 it was known that an increase in systolic pressure is accompanied by a greater myocardial oxygen cost than a proportionate increase in stroke volume. Recent investigators have related myocardial oxygen consumption to the product of the mean systolic pressure and the heart rate, or to the integral of systolic pressure in time. In the isovolumetrically contracting ventricle, my...

Myocardial contraction-relaxation coupling.

Since the pioneering work of Henry Pickering Bowditch in the late 1800s to early 1900s, cardiac muscle contraction has remained an intensely studied topic for several reasons. The heart is located centrally in our body, and its pumping motion demands the attention of the observer. The contraction of the heart encompasses a complex interplay of mechanical, chemical, and electrical properties, an...

Myocardial oxygen consumption change predicts left ventricular relaxation improvement in obese humans after weight loss.

Obesity adversely affects myocardial metabolism, efficiency, and diastolic function. Our objective was to determine whether weight loss can ameliorate obesity-related myocardial metabolism and efficiency derangements and that these improvements directly relate to improved diastolic function in humans. We studied 30 obese (BMI >30 kg/m2) subjects with positron emission tomography (PET) (myocardi...

Velocity of contraction as a determinant of myocardial oxygen consumption.

SONNENBLICK, EDMUND H., JOHN Ross, JR., JAMES W. COVELL, GERARD A. KAISER, AND EUGENE BRAUNWALD. Velocity of contraction US a determinant of rnyocardial oxygen consumption. Am, J, Physiol. 2og(5) : 919-927. Ig65.-In 12 dogs on rightheart bypass with heart rate, stroke volume, and aortic pressure constant, the velocity of contraction was augmented comparably by three fundamentally distinct inter...

Myocardial oxygen consumption during exercise in fasting and lipemic subjects.