Hemodynamic response to isometric handgrip in acute myocardial infarction

Thirteen patients underwent right cardiac catheterization during the first 24 hours after the onset of symptoms of acute myocardial infarction. All had normal (less than 12 mm Hg) pulmonary arterial diastolic pressure or normal mean pulmonary wedge pressure (7.6 +/- 0.6 mm Hg). The patients did isometric forearm contraction to a measured level of 100 mm Hg. All patients had elevation of systemic systolic blood pressure, with a mean rise of 14.2 +/- 2.9 mm Hg; heart rate rose by 12 +/- 2 beats per minute. When compared to a control group, patients with acute myocardial infarction had a significant (P less than 0.005) elevation of 5.4 +/- 1.3 mm Hg in the pulmonary arterial diastolic or pulmonary wedge pressure. This may be a result of either increased left ventricular stiffness or decreased myocardial functional reserve. In the setting of acute myocardial infarction, patients with normal left ventricular filling pressures have abnormal ventricular performance. Isometric effort is poorly tolerated and should be avoided.