The Effect of Isometric Exercise on the Left Ventricular Volume in Normal Man

The effect of isometric handgrip exercise (IHG) on left ventricular (LV) size and performance was studied noninvasively on 15 normal subjects at rest and at the end of 3 min of IHG at 50% of maximum contraction. Left ventricular internal diameter was measured at end-diastole and end-systole on LV echograms, the indirect carotid pulse was recorded, and blood pressure measured by sphygmomanometry. Using the cube formula, LV end-diastolic (EDVI) and end-systolic (ESVI) volume indices were computed, and stroke (SI) and cardiac (CI) indices were derived. Mean blood pressure (BPm) and systemic vascular resistance (SVR) were calculated from these data by a technique previously described. In comparison to values at rest, IHG resulted in a significant (P < 0.01) rise in CI (3.5 ± 0.2 to 4.4 ± 0.3 L/min/m2), BPm (87 ± 2 to 120 ± 4 mm Hg) and heart rate (79 ± 3 to 97 ± 4 beats/min). The product (SI × BPm), used as an index of LV stroke work, increased substantially (52 ± 3 to 74 ± 4 gm-m/m2). No significant change was noted in EDVI (60 ± 4 to 62 ± 3 ml/m2), SI (44 ± 2 to 46 ± 2 ml/m2), and SVR (1209 ± 69 to 1275 ± 63 dynes/sec/cm−5).Thus normal hearts responded to IHG by increasing CI through tachycardia and pumping the same SI against increased afterload, without utilizing diastolic volume reserves. These data support the hypothesis that isometric muscular exercise leads to an augmentation of LV myocardial contractility in normal man.

[1]  L. Dexter,et al.  Changes in the inotropic state of the left ventricle during isometric exercise. , 1973, British heart journal.

[2]  L. Horwitz,et al.  Comparison of isometric exercise and angiotensin infusion as stress test for evaluation of left ventricular function. , 1973, The American journal of cardiology.

[3]  W. Grossman,et al.  Determination of Systemic Vascular Resistance by a Noninvasive Technic , 1973, Circulation.

[4]  W. Rutishauser,et al.  Left ventricular dynamics during handgrip. , 1972, British heart journal.

[5]  H Feigenbaum,et al.  Ultrasound measurements of the left ventricle. A correlative study with angiocardiography. , 1972, Archives of internal medicine.

[6]  W. Parmley,et al.  Effects of Isometric Exercise on Cardiac Performance: The Grip Test , 1971, Circulation.

[7]  N. Fortuin,et al.  Determination of Left Ventricular Volumes by Ultrasound , 1971, Circulation.

[8]  R. Russell,et al.  Left Ventricular Volumes and Ejection Fraction by Echocardiography , 1971, Circulation.

[9]  G. Diamond,et al.  Diastolic pressure-volume relationship in the canine left ventricle. , 1971, Circulation research.

[10]  D C Harrison,et al.  Ultrasonic Cardiac Echography for Determining Stroke Volume and Valvular Regurgitation , 1970, Circulation.

[11]  J. W. Kennedy,et al.  Ultrasonic determination of left ventricular wall motion in normal man. Studies at rest and after exercise. , 1970, American heart journal.

[12]  H Feigenbaum,et al.  Estimation of right and left ventricular size by ultrasound. A study of the echoes from the interventricular septum. , 1969, The American journal of cardiology.

[13]  J. Ross,et al.  Assessment of Cardiac Function , 1969 .

[14]  A. C. Burton,et al.  Recommendations for Human Blood Pressure Determination By Sphygmomanometers , 1981, Circulation.

[15]  K. Donald,et al.  Effect of intravenous propranolol on the systemic circulatory response to sustained handgrip. , 1966, The American journal of cardiology.

[16]  O. Lindeneg,et al.  COMPLICATIONS IN 4,413 CATHETERIZATIONS OF THE RIGHT SIDE OF THE HEART. , 1965, American heart journal.

[17]  P. W. Humphreys,et al.  THE CIRCULATIORY EFFECTS OF SUSTAINED VOLUNTARY MUSCLE CONTRACTION. , 1964, Clinical science.

[18]  H. Badeer,et al.  CONTRACTILE TENSION IN THE MYOCARDIUM. , 1963, American heart journal.

[19]  J. Ross,et al.  The ventricular end-diastolic pressure. Appraisal of its value in the recognition of ventricular failure in man. , 1963, The American journal of medicine.