High-fidelity left ventricular pressure measurements for the assessment of cardiac contractility in man
| Autor: | W. Rutishauser, Hans P. Krayenbuehl, H C Mehmel, I. Amende, Pierre Wirz |
|---|---|
| Rok vydání: | 1973 |
| Předmět: |
Adult
medicine.medical_specialty Adolescent Heart Diseases Heart Ventricles Physical Exertion Cardiomyopathy Heart Valve Diseases Cardiomegaly Coronary Disease Isometric exercise Aortic Coarctation Heart Septal Defects Atrial Coronary artery disease Contractility Stress Physiological Internal medicine medicine Humans Child Cardiac cycle business.industry Hemodynamics Heart Middle Aged medicine.disease Stenosis medicine.anatomical_structure Ventricle Computers Analog Heart Function Tests Ventricular pressure Cardiology Cardiology and Cardiovascular Medicine business Cardiomyopathies |
| Zdroj: | The American journal of cardiology. 31(4) |
| ISSN: | 0002-9149 |
| Popis: | Left ventricular contractility was assessed in 110 patients by use of Vmax values derived from high-fidelity left ventricular pressure measurements. Instantaneous velocity of shortening of the contractile elements (V CE ) throughout the isovolumic phase of left ventricular systole was calculated by an analog computer using the formula: V CE in muscle lengths (ML)/ sec = ( dP / dt )/28 · P where P represents total left ventricular pressure and dP/dt its first derivative. Vmax was obtained by manual straight line extrapolation of the descending portion of the pressure-velocity curves. Group 1 (control subjects) consisted of 25 patients with no or minimal loading of the left ventricle. Vmax in Group 1 was 1.86 ML/sec. Group 2 consisted of 25 patients with atrial septal defect and Group 3 included 11 patients with slight left ventricular pressure load. In Groups 2 and 3, the Vmax value was not significantly different from that of Group 1. However, in Group 4, which consisted of 23 patients with moderate to severe left ventricular pressure load, Vmax was significantly reduced (1.53 ML/sec); in Group 5, which consisted of 14 patients with coronary artery disease and 6 patients with cardiomyopathy, Vmax was 1.21 ML/sec; and in Group 6, comprising 6 patients with mitral stenosis, Vmax was 1.26 ML/sec. In individual patients in Groups 3 to 5, assessment of contractility by comparison with resting Vmax values was not always satisfactory because of overlap with the range of the control subjects. Isometric exercise by handgrip carried out in 44 patients allowed further differentiation of individual contractile function. In Groups 1 and 2, the response to handgrip was characterized by a significant increase of Vmax with no alterations or changes not exceeding +4 mm Hg of left ventricular end-diastolic pressure. In Groups 3 to 5, we observed normal responses, as well as abnormal reaction to handgrip (increase of Vmax associated with an increase of left ventricular end-diastolic pressure that exceeded 4 mm Hg) and pathologic reaction to handgrip (decrease of Vmax accompanied by an increase of left ventricular end-diastolic pressure). Seven of 13 patients with a normal resting Vmax showed an abnormal or a pathologic reaction. A normal response to handgrip was observed in a few patients with depressed resting Vmax. It is concluded that identification of individual patients with impaired myocardial contractile function requires determination of Vmax both at rest and during an additional stress such as isometric exercise. |
| Databáze: | OpenAIRE |
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