Youhei Yamakawa

Optimal Programming of the Atrioventricular Delay Using the Phonocardiogram

Purpose: To predict the optimal atrioventricular (AV) delay using the phonocardiogram (PCG).

Effect of Biventricular Pacing on Myocardial Glucose Metabolism in Patients with Heart Failure Using Fluoro‐18‐Deoxyglucose Positron Emission Tomography

OHKUSU, Y., et al.: Effect of Biventricular Pacing on Myocardial Glucose Metabolism in Patients with Heart Failure Using Fluoro‐18‐Deoxyglucose Positron Emission Tomography. Biventricular pacing has recently been found beneficial in the treatment of congestive heart failure (CHF). Meanwhile, positron emission tomography (PET) has emerged as a new method to analyze glucose metabolism in the heart. Five patients (mean age 68.8 ± 8.1  years , 4 men) who received biventricular pacing therapy for 5.8 ± 6.6 weeks for CHF were studied. Myocardial glucose metabolism was evaluated by PET with fluoro‐18‐deoxyglucose (18F‐FDG), and percent uptake (%uptake) of 18F‐FDG was calculated during biventricular pacing and compared with that during 1 hour of conventional RV pacing. Biventricular pacing was associated with a significant decrease in NYHA functional Class from 3.67 ± 0.52 to 2.50 ± 0.55. After 18F‐FDG PET, three of five patients remained clinically stable, and two died during follow‐up. Mean 18F‐FDG %uptake during biventricular pacing was not different than during short‐term RV pacing ( 62.1 ± 18.4 vs. 63.6 ± 17.0% ). However, patients who remained clinically stable had a lower value of 18F‐FDG %uptake in the septal region than patients who died ( 46.9 ± 5.6 vs 80.3 ± 1.3%, P < 0.01 ). One patient whose cardiac function improved significantly also had a small septal region of decreased 18F‐FDG uptake during RV pacing. In conclusion, biventricular pacing therapy was effective in this small group of patients with severe, drug‐resistant CHF. An evaluation of the effects of biventricular pacing on glucose metabolism in the subacute phase may help identify patients with a favorable long‐term response to this therapy. (PACE 2003; 26[Pt. II]:144–147)

Anti-tachycardia therapy can improve altered cardiac adrenergic function in tachycardia-induced cardiomyopathy.

We investigated whether anti-tachycardia therapy might improve the altered cardiac adrenergic and systolic function in tachycardia-induced cardiomyopathy (TC) in contrast to dilated cardiomyopathy (DCM). The subjects were 23 patients with heart failure, consisting of 8 patients with TC (43.6±10.0 yrs) and 15 with DCM (45.3±8.2 yrs). TC was determined as impairment of left ventricular function secondary to chronic or very frequent arrhythmia during more than 10% of the day. All patients were receiving anti-tachycardia treatment. Cardiac123I-MIBG uptake was assessed as the heart/mediastinum activity ratio (H/M) before and after treatment. LVEF was also assessed. In the baseline study, H/M and LVEF showed no difference between TC and DCM (2.21 ±0.44 vs. 2.10±0.42, 35.3±13.1 vs. 36.0±10.9%, respectively). After treatment, the degree of change in H/M and LVEF differed significantly (0.41±0.34 vs. 0.08±0.20,20.5±14.4 vs. −2.1 ±9.6%, p<0.01). In TC, heart failure improved after a shorter duration of treatment (p<0.05). In conclusion, anti-tachycardia therapy can improve altered cardiac adrenergic function and systolic function in patients with TC over a shorter period than in those with DCM.