Circadian variation of cardiac autonomic nervous activity is well preserved in patients with mild to moderate chronic heart failure: effect of patient position.

BACKGROUND: It remains unclear whether circadian variation (CV) of cardiac autonomic nervous activity (CANA) is preserved in patients with chronic heart failure (CHF) as in healthy subjects. We have demonstrated that CANA in CHF patients is largely affected by patient recumbent position. METHODS: We studied eight mild to moderate CHF patients and eight age, sex-matched healthy subjects. Each subject underwent 24-h ambulatory ECG monitoring. One channel was used to record the CM5 lead, and another to record the signal of patient position from a newly developed, small-sized detector. By using spectral analysis of heart rate variability, frequency-domain measures were calculated. Normalized high-frequency (HF: 0.15-0.40 Hz) power was used as an index of vagal activity and the low frequency (LF: 0.04-0.15 Hz)/HF power ratio was used as an index of sympathovagal balance. These indexes in the same recumbent position were compared between night (2:00-4:00 a.m.) and morning (6:00-8:00 a.m.). RESULTS: In healthy subjects, a definite CV of CANA was observed in each recumbent position. In patients with CHF, in each position, normalized HF power was lower in the morning than at night, whereas LF/HF was higher in the morning than at night. Thus, CANA in CHF patients is influenced not only by patient position but also by the time of day. CONCLUSION: CV of CANA in mild to moderate CHF patients is well preserved when taking patient position into consideration.

Acute and long-term outcomes of rotational atherectomy in small (< 3.0 mm) coronary arteries.

Conventional balloon angioplasty (BA) of small coronary arteries (SCA) is followed by a high rate of restenosis. Rotational atherectomy may be effective as an alternate treatment of stenoses unsuitable for other devices. The purpose of this study was to assess the efficacy of RA in the treatment of SCA. A retrospective analysis was performed of 226 lesions in 159 consecutive patients who underwent RA of SCA (mean diameter = 2.36 +/- 0.49 mm). One hundred forty-eight lesions (65.5%) were type B2 or C of AHA/ACC criteria. Follow-up angiography was performed at 3 and 6 months after the procedure. Procedural success was achieved in 96.9% of patients. The mean burr-to-artery ratio was 0.74 +/- 0.17. Adjunctive BA and stent implantation were needed in 94.2% and 22.6% of lesions, respectively. Minimal lumen diameter (MLD) increased from 0.66 +/- 0.35 mm to 1.97 +/- 0.58 mm (P < 0.01). Angiographic complications consisted of acute reclosure (3.5%), no reflow/slow flow (12.4%), and coronary artery perforation (1.8%). No death, Q-wave myocardial infarction (MI), or coronary artery bypass graft (CABG) occurred during the initial hospitalization. Restenosis rates at 3 and 6 months were 40.6% and 44.2%, respectively, and target lesion revascularization (TLR) rates were 28.5% and 33.0%, respectively. Restenosis and TLR rates during follow-up were comparable among patients who underwent RA + adjunctive BA versus patients who underwent RA + stenting. Long-term clinical follow-up was complete in 143 patients over a mean period of 348 +/- 166 days. The survival free from cardiac death, MI, CABG or repeated BA was 59.6% at 1 year. In conclusion, RA of SCA has relatively high restenosis rates, but may be appropriate for more complex, calcified lesions unsuitable for other devices.

Effect of intracoronary nicorandil administration on preventing no-reflow/slow flow phenomenon during rotational atherectomy.

A major limitation of the rotational atherectomy (RA) procedure is the occurrence of the no-reflow/slow flow phenomenon and the optimal strategy is still evolving. Recent clinical studies have demonstrated the beneficial effects of nicorandil, an adenosine triphosphate (ATP)-sensitive potassium channel opener, on no-reflow in patients with acute myocardial infarction. The purpose of this study was to evaluate the effect of nicorandil on no-reflow/slow flow phenomenon during RA procedures. Sixty-one patients who underwent RA of complex coronary lesions were randomly divided into 2 groups: (i) nicorandil cocktail (n=24 patients, 37 lesions) and (ii) verapamil cocktail (n=37 patients, 63 lesions). In each group, the drug cocktail mixed with pressurized saline was infused through the 4Fr Teflon sheath of the rotablator system during the RA procedure. In the nicorandil group, the drug cocktail consisted of 24 mg of nicorandil, 5 mg of nitroglycerin, and 10,000 U of heparin. In the verapamil group, the drug cocktail consisted of 10 mg of verapamil, 5 mg of nitroglycerin, and 10,000 U of heparin. Baseline and procedure characteristics did not differ between the 2 groups. RA was performed successfully, and death, Q-wave myocardial infarction, or emergency coronary artery bypass surgery did not occur in any patients. The no-reflow/slow flow phenomenon was observed in 11/63 (17.4%) lesions of the verapamil group, but in only 1/37 (2.7%) lesions of the nicorandil group (p=0.03). No untoward complications were observed during nicorandil infusion. These data indicate that the intracoronary continuous infusion of nicorandil during RA procedures is easy and safe, and prevents no-reflow/slow flow phenomenon more effectively than infusion of verapamil.

Shunt between the ventricular chamber and coronary arteries preserves left ventricular function in acute myocardial infarction.

It is controversial whether newly created channels made by transmyocardial laser revascularization are functionally significant, so the present study evaluated the shunt flow from the left ventricular (LV) cavity to the ischemic myocardium in 51 patients with acute myocardial infarction (AMI) caused by complete occlusion of the proximal left anterior descending coronary artery. All patients underwent left heart catheterization within 24 h of onset and all underwent successful coronary reperfusion using primary coronary angioplasty with no angiographic restenosis on follow-up coronary angiography (CAG). The presence of the LV shunt flow was evaluated by selective left CAG after successful reperfusion. The LV global ejection fraction (EF) and regional function (centerline method) were analyzed by ventriculography in both the acute and chronic phases. The patients were divided into the 3 groups (Group A, no LV shunt without collaterals, n=20; Group B, no LV shunt with collaterals, n=24; Group C, LV shunt with collaterals, n=7). There was no difference in the grade of collateral circulation between Groups B and C. The improvements in LVEF and regional function from the acute phase to the chronic phase were significantly greater in Group C than in Groups A and B. Not only collateral circulation but also LV shunt contributes to the functional recovery of infarct myocardium in patients with AMI.