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[Mitral regurgitation in hypertrophic cardiomyopathy: an analysis with two-dimensional ultrasonic Doppler
Insights
Ultrasonic Doppler echocardiography revealed mitral regurgitation in all obstructive and half of nonobstructive hypertrophic cardiomyopathy cases. This finding helps clarify the origin of systolic murmurs in hypertrophic cardiomyopathy.
Area of Science:
- Cardiology
- Medical Imaging
- Physiology
Context:
- Hypertrophic cardiomyopathy (HCM) is a complex cardiac condition.
- Noninvasive assessment of intracardiac blood flow is crucial for understanding HCM pathophysiology.
- Mitral regurgitation (MR) is a common complication in HCM, but its characteristics require further elucidation.
Purpose:
- To noninvasively study intracardiac blood flow patterns in the left ventricle and left atrium in patients with hypertrophic cardiomyopathy.
- To characterize the incidence and features of mitral regurgitation in hypertrophic cardiomyopathy using Doppler echocardiography.
- To investigate the relationship between mitral regurgitation and early systolic murmurs in hypertrophic cardiomyopathy.
Summary:
- Doppler echocardiography identified mitral regurgitant signals in all cases of obstructive HCM and 50% of nonobstructive HCM.
- Mitral regurgitant flow patterns differed between obstructive (widespread) and nonobstructive (localized) HCM, distinct from other MR etiologies.
- Doppler findings correlated well with left ventriculography, and early systolic murmurs were strongly associated with mitral regurgitation.
Impact:
- Provides valuable insights into the hemodynamics of mitral regurgitation in hypertrophic cardiomyopathy.
- Enhances the noninvasive diagnostic capabilities for assessing mitral regurgitation in HCM.
- Contributes to a better understanding of the mechanisms underlying systolic murmurs in hypertrophic cardiomyopathy.
Abstract:
Intracardiac blood flow pattern in the left ventricle and left atrium was noninvasively studied by the ultrasonic pulsed Doppler flowmeter incorporated with a real-time, phased array two-dimensional echocardiography in 28 cases of hypertrophic cardiomyopathy. Emphasis was placed on the incidence and characteristic features of mitral regurgitation in this condition. The relationship of mitral regurgitation with an early systolic murmur was also studied. The results were as follows: 1) A mitral regurgitant signal by Doppler technique was noted in all cases of hypertrophic obstructive cardiomyopathy and in half of the cases of hypertrophic nonobstructive cardiomyopathy. 2) The Doppler signal of mitral regurgitation began immediately after the first heart sound. 3) The mitral regurgitant flow spread over the left atrium or directed toward the posterior half of the left atrium in the obstructive cases. However, it was localized in the vicinity of the mitral orifice in the nonobstructive cases. These findings were different from those in rheumatic mitral regurgitation or idiopathic mitral valve prolapse. 4) The findings on mitral regurgitation by the Doppler technique exhibited a satisfactory correspondence to those by left ventriculography. 5) The early part of the systolic murmur in hypertrophic cardiomyopathy was considered to be more closely related to mitral regurgitation than a turbulent forward flow due to outflow obstruction. Therefore, mitral regurgitation might have some contribution in causing a murmur in the latter period of systole.