CLINICAL STUDIES
Systolic ejection murmurs in the era of modern cardiology
What do we really know?
Joseph P. Murgo, MD, FACCa
a Heart and Vascular Institute of Texas, San Antonio, Texas, USA
Manuscript received July 20, 1998;
accepted July 22, 1998.
Address for correspondence: Dr. Joseph P. Murgo, CEO/Medical Director, Heart and Vascular institute of Texas, 1935 NE Loop 410, San Antonio, Texas 78217 jmurgo{at}txdirect.net
The basics of pulsatile ejection dynamics are reviewed in order to clarify the relationships among left ventricular and aortic pressures, intra-left ventricular and aortic flow velocities, and cardiovascular sound. The principles of turbulent flow are examined using the Reynolds number concept, and the evidence for cause-and-effect relationships between turbulent flow and murmur generation is presented. Examples of hemodynamics and phonocardiography are given for normal subjects and are compared to patients with aortic stenosis and hypertrophic cardiomyopathy. The concepts presented are used to analyze the results of a new study suggesting increased intraventricular velocities as a new cause for systolic murmurs in adults.
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Abbreviations and Acronyms
| | AO | = aorta, aortic | | HCM | = hypertrophic cardiomyopathy | | LV | = left ventricular; left ventricle | | LVH | = left ventricular hypertrophy | | LVOT | = left ventricular outflow tract | | PVC | = premature ventricular contraction | | Q | = volumetric flow (cc/sec) | | SAM | = systolic anterior motion of the mitral valve |
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