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Pulsed Doppler echocardiographic assessment of transmitral flow in pacing-induced angina pectoris
C Toda1, K Fujitani, M Takeuchi
1First Department of Internal Medicine, Kobe University School of Medicine, Japan.
Insights
During angina in coronary artery disease (CAD) patients, impaired left ventricular (LV) rapid filling was observed. Atrial contraction incompletely compensated for reduced transmitral flow during acute myocardial ischemia.
Area of Science:
- Cardiology
- Echocardiography
- Physiology
Background:
- Coronary artery disease (CAD) can lead to acute myocardial ischemia.
- Left ventricular (LV) filling dynamics are crucial for cardiac function.
Purpose of the Study:
- To analyze transmitral flow patterns during anginal attacks in CAD patients.
- To investigate the impact of acute ischemia on LV filling parameters.
Main Methods:
- Pulsed Doppler echocardiography was used to assess transmitral flow.
- Angina was provoked by atrial pacing in 11 CAD patients.
- LV filling was divided into four intervals to quantify filling volumes.
Main Results:
- During angina, the interval from peak rapid filling to end of rapid filling (IR2) decreased significantly (p < 0.005).
- Peak rapid filling velocity (peak R) decreased, while the filling time (Tr1) prolonged.
- Atrial contraction filling (IA) increased, but did not fully compensate for the reduced rapid filling.
Conclusions:
- Acute myocardial ischemia in CAD impairs LV rapid filling.
- Reduced transmitral flow during early diastole (IR2) is a key indicator of this impairment.
- Atrial contraction provides incomplete compensation for impaired LV filling during ischemia.
Abstract:
We analyzed transmitral flow using pulsed Doppler echocardiography during anginal attack provoked by atrial pacing in 11 patients with coronary artery disease (CAD). Left ventricular (LV) filling period was divided into 4 time intervals (Tr1: the time interval to peak velocity of rapid filling (peak R), Tr2: the time interval from peak R to the end of rapid filling, Ts: the time interval of slow filling, Ta: the time interval of atrial contraction). The velocity in each interval was integrated by planimeter as IR1, IR2, IS or IA which indicates relative filling volume in each interval. During angina, IR1 was unchanged due to prolongation of Tr1 (82 +/- 21 to 102 +/- 23 msec, p less than 0.02), despite a decrease in peak R (54 +/- 11 to 43 +/- 11 cm/sec, p less than 0.005), while IR2 decreased (5.8 +/- 1.9 to 4.3 +/- 1.4 cm, p less than 0.005) and IA increased (6.7 +/- 1.4 to 7.3 +/- 1.3 cm, p less than 0.005). In conclusion, these results suggested that in acute myocardial ischemia in CAD a decrease in transmitral flow from the time of peak R to the end of rapid filling (IR2) reflected the impairment of the LV rapid filling, which was incompletely compensated by an increase in atrial contraction.