Author + information
- Received August 20, 1985
- Revision received April 1, 1986
- Accepted April 7, 1986
- Published online August 1, 1986.
- Samuel S. Gidding, MD1,2,
- A. Rebecca Snider, MD, FACC*,1,
- Albert P. Rocchini, MD1,
- Jane Peters1 and
- Rebecca Farnsworth1
- ↵*Address for reprints: A. Rebecca Snider, MD, F1609, CS. Mott Children's Hospital, Ann Arbor, Michigan 48109-0010.
Altered left ventricular filling patterns in hypertrophic cardiomyopathy have been demonstrated by M-mode echocardiography and radionuclide techniques. Because pulsed Doppler ultrasound provides the capability to directly measure blood flow velocity across the mitral valve, it was hypothesized that this technique would be useful for demonstrating left ventricular filling abnormalities. Simultaneous Doppler utrasound examination of the left ventricular inflow, M-mode echocardiograms and phonocardiograms were performed in 17 children and young adults: 10 with hypertrophic cardiomyopathy (aged 6 to 20 years) and 7 with a normal heart (aged 10 to 18 years). From the Doppler studies, measurements of various diastolic time intervals, peak flow velocity during rapid filling (E velocity) and peak flow velocity during atrial contraction (A velocity) were made. Several areas within the Doppler flow envelope were calculated: first 33% of diastole (0.33 area), first 50% of diastole, triangle under the E velocity (E area) and triangle under the A velocity (A area). These were expressed as a percent of area under the total flow envelope.
From the M-mode studies, left ventricular endocardial echoes were digitized and peak rates of increase in left ventricular dimension were determined and normalized for end-diastolic dimension. Diastolic time intervals, including isovolumic relaxation time, were calculated using the phonocardiogram to determine end-systole. The E velocity was lower (0.71 ± 0.23 versus 0.91 ± 0.11 m/s, p < 0.05), 0.33 area/total area was less (0.46 ± 0.11 versus 0.58 ± 0.08, p < 0.05) and the isovolumic relaxation time was prolonged (56 ± 2 versus 31 ± 1 ms, p < 0.05) in patients with hypertrophic cardiomyopathy. Other Doppler and M-mode time intervals, rates of left ventricular dimension change, A velocity and the remaining Doppler areas were not significantly different between groups.
In conclusion, altered patterns of left ventricular filling are demonstrable by Doppler ultrasound techniques in hypertrophic cardiomyopathy. The prolonged isovolumic relaxation time suggests a diminution in active left ventricular relaxation. The decreased percent of the total Doppler area in the first 33% of diastole and the decreased peak E velocity suggest diminished flow during the rapid filling phase of diastole.
- Received August 20, 1985.
- Revision received April 1, 1986.
- Accepted April 7, 1986.
- American College of Cardiology Foundation