Acute Hemodynamic Benefits of Bi-Atrial Atrioventricular Sequential Pacing With the Optimal Atrioventricular Delay
Atsushi Doi, MD,
Masahiko Takagi, MD*,
Iku Toda, MD,
Minoru Yoshiyama, MD,
Kazuhide Takeuchi, MD and
Junichi Yoshikawa, MD, FACC
Department of Internal Medicine and Cardiology, Osaka City University Graduate School of Medicine, Osaka, Japan
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Figure 1 The optimization of the atrioventricular (AV) delay. We defined the optimal AV delay as the time when the end of the atrial filling wave (A) on the transmitral flow coincided with the onset of the first heart sound (S1), using simultaneous heart sound monitoring. Dotted line indicates the onset of the first heart sound. E = the early filling wave; S2 = the second heart sound.
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Figure 2 (A) Sample of the echocardiographic measurements. (B) Representative patterns of transmitral Doppler flow during AV sequential pacing with the optimal AV delays. White bars indicate the atrial pacing spike. (a) High right atrial (HRA) pacing; (b) Coronary sinus (CS) pacing; (c) Bi-atrial (BiA) pacing. The BiA pacing produced the most increased peak velocity of the atrial filling wave (A Vmax) and the shortest interval from the atrial pacing spike on the electrocardiogram to the peak of the atrial filling wave (S-A peak). E Vmax = peak velocity of the early filling wave; TVI = mitral flow time velocity integral; other abbreviations as in Figure 1.
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Figure 3 Interatrial conduction delay. Interatrial conduction delay was estimated by measuring the interval from S2 at high right atrial (HRA) to the first sharp deflection of A2 at the distal coronary sinus (CS), and was calculated as the time interval between atrial response at the distal CS (A1A2) and the stimulus coupling interval (S1S2), that is, A1A2 – S1S2. The maximal interatrial conduction delay was then determined. Abbreviations as in Figure 2.
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Figure 4 (A) Comparison of P-wave duration between baseline and the three pacing sites. P-wave duration is the shortest during bi-atrial (BiA) pacing. (B) Comparison of cardiac output (CO) between the three pacing sites at both pacing rates. The BiA pacing significantly produced the most increased CO. (C) Comparison of pulmonary capillary wedge pressure (PCWP) between the three pacing sites at both pacing rates. BiA pacing resulted in the most significant improvement. (D) Comparison of systolic blood pressure (SBP) between the three pacing sites at both pacing rates. BiA pacing significantly produced the most increased SBP. Solid line indicates data at 80 beats/min. Dotted line indicates data at 100 beats/min. Other abbreviations as in Figure 2.
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Figure 5 (A) Comparison of E Vmax at a heart rate of 80 beats/min at the three pacing sites. The E Vmax was significantly larger during bi-atrial (BiA) pacing than during high right atrial (HRA) pacing; however, there was no significant difference between BiA and coronary sinus (CS) pacing. (B) Comparison of A Vmax at 80 beats/min between the three pacing sites; BiA pacing significantly produced the most increased A Vmax. (C) Comparison of TVI between the three pacing sites; BiA pacing significantly produced the most increased TVI. (D) Comparison of S-A peak at 80 beats/min between the three pacing sites; S-A peak was significantly the shorter during CS and BiA pacing than during HRA pacing, although there was no significant difference between BiA and CS pacing. (E) Comparison of the optimal AV delay between the three pacing sites. The optimal AV delay was significantly shorter during CS or BiA pacing than during HRA pacing; however, there was no significant difference between CS and BiA pacing. Solid line indicates data at 80 beats/min. Dotted line indicates data at 100 beats/min.
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S-A peak,