Borg's exertion scale did not coincide with ventilatory anaerobic threshold in atrial fibrillation patients with restored sinus rhythm after ablation.

The determination of precise exercise intensity is essential for effective exercise rehabilitation. The Borg rating of perceived exertion category ratio (CR) scale is utilized to prescribe an appropriate level of exertion intensity. A Borg CR of approximately 13 coincides with the ventilatory aerobic threshold (VAT). Patients with atrial fibrillation (AF) exhibit various symptoms. We hypothesized that the workload at Borg CR13 (Borg CR13-Watt) differs from the workload at the VAT level (VAT-Watt) in AF patients with restored sinus rhythm (SR) following ablation. Accordingly, the relationship between Borg CR13-Watt and VAT-Watt was studied in patients with restored SR. Cardiopulmonary exercise testing (CPET) was performed at 101±88 days after ablation in 150 patients using a bicycle ergometer. No adverse events were observed during CPET. Borg CR13-Watt was significantly higher than VAT-Watt (67.2±27.8 Watt vs. 54.7±17.6 Watt, P<0.0001). Borg CR13-Watt showed significant linear regression with VAT-Watt (regression coefficient, 0.49, P<0.01; correlation coefficient, 0.80, P<0.01). Higher Borg CR13-Watt was associated with greater differences between Borg CR13-Watt and VAT-Watt (ΔWatt). The Bland-Altman plot showed nonconcordance between the two. Male sex, use of antiarrhythmic drugs, and smoking had contributed to the increased ΔWatt. Duration from ablation to time of CPET did not correlate with ΔWatt. Therefore, Borg CR13-Watt did not coincide with VAT-Watt in patients with restored SR. Higher Borg CR13-Watt was associated with greater ΔWatt. Prescribing exertion intensity as determined solely by perceived exertion is inadequate. CPET is required to determine the precise exercise intensity in AF patients with restored SR after ablation.

Correlation of the peak oxygen consumption and ventilatory aerobic threshold by cardiopulmonary exercise testing with atrial fibrillation recurrences after ablation in patients with paroxysmal atrial fibrillation.

BACKGROUND: The cardiopulmonary function is hypothesized to be associated with atrial fibrillation/atrial tachyarrhythmia (AF/AT) recurrence after AF ablation. PURPOSE: To clarify the relationship between the cardiopulmonary function after successful ablation and AF/AT recurrence. METHODS: We examined 31 patients with paroxysmal AF who underwent AF ablation. Cardiopulmonary exercise testing (CPET) was performed at 1month after the ablation. A continuously increasing loading method on a bicycle ergometer was employed for the CPET. RESULTS: No adverse events, including AF/AT recurrence, occurred during the CPET. Among 31 patients, AT/AF recurrence was observed in seven (23%). The ventilatory anaerobic threshold (VAT) and peak oxygen consumption (VO2) were significantly higher in patients without AF/AT recurrence than in those with AT/AF recurrences (peak VO2 23.6 ± 5.7 vs 17.2 ± 4.1 mL/kg/min; VAT, 16.7 ± 2.8 vs 13.8 ± 2.7 mL/min/kg). The areas under the receiver operating characteristic curve for the peak VO2 and VAT were 0.786 (P < .01) and 0.789(P < .01), respectively. Both indices had a sensitivity of 70%-80% and specificity of 70%-80% for predicting AT/AF recurrence. Similar results were obtained for the percent values of the predicted peak VO2 and VAT. CONCLUSIONS: The present pilot study found that CPET can be performed safely at approximately 1 month after AF ablation. The peak VO2 and VAT were significantly associated with AT/AF recurrence. The peak VO2 and VAT were thought to provide helpful information regarding AT/AF recurrence.

Eosinophil Cationic Protein Shows Survival Effect on H9c2 Cardiac Myoblast Cells with Enhanced Phosphorylation of ERK and Akt/GSK-3ß under Oxidative Stress.

Eosinophil cationic protein (ECP) is well known as a cationic protein contained in the basic granules of activated eosinophils. Recent studies have reported that ECP exhibits novel activities on various types of cells, including rat neonatal cardiomyocytes. Here we evaluated the effects of ECP on rat cardiac myoblast H9c2 cells. Our results showed that ECP enhanced the survival of the cells, in part by promoting the ERK and Akt/GSK-3ß signaling pathways. ECP attenuated the cytotoxic effects of H2O2 on H9c2 cells as well as the production of reactive oxygen species, the number of apoptotic cells and caspase 3/7 activity in the cells. In conclusion, ECP activated the ERK and Akt/GSK-3ß pathways, resulting in anti-oxidative effects on H9c2 cells that attenuated apoptosis.

Neointimal calcification after stenting and chronic kidney disease.

The timing and incidence of neointimal calcification after stenting (NIC) is largely unknown. The purpose of our study was to elucidate the characteristics of NIC. The presence of NIC in patients who underwent intravascular ultrasound between June 30, 2009 and June 30, 2012 was analyzed. The patients were divided into two groups based on the follow-up period: < 365 days or ≥ 365 days. A total of 181 images were analyzed. Those with NIC had a lower estimated glomerular filtration rate [51 (6-60) versus 61 (52-72) mL/minute/1.73 m²; P < 0.01] and longer time after stenting [3198 (1710-3684) versus 211 (180-516) days; P < 0.01] compared to those without NIC. NIC during short-term follow-up was observed only in patients who were on hemodialysis. On the other hand, NIC in the long-term follow-up was observed only in patients with bare metal stents. The development of NIC was related to renal function and time after stenting. NIC in the short-term and the long-term follow-up was observed only in patients who were on hemodialysis and who were implanted with a bare metal stent, respectively.

Safety of and tolerance to adenosine infusion for myocardial perfusion single-photon emission computed tomography in a Japanese population.

BACKGROUND: Adenosine has been available for use in myocardial perfusion single-photon emission computed tomography (SPECT) in Japan since 2005. The purpose of this study was to evaluate the safety of and tolerance to thallium-201 myocardial perfusion SPECT with intravenous adenosine infusion in Japanese patients with suspected coronary artery disease. METHODS AND RESULTS: Two hundred and six consecutive patients who underwent an adenosine infusion (120 mug . kg(-1) . min(-1)) SPECT at Sumitomo Besshi Hospital (Niihama, Japan) were investigated. The effects of adenosine infusion were monitored for each patient. A coronary angiography was performed in 81 patients. Adenosine infusion significantly decreased blood pressure and increased heart rate. Adverse reactions were observed in 161 patients (78.2%). Most reactions were transient, disappearing soon after the termination of adenosine infusion. No serious adverse reactions, such as acute myocardial infarction or death, occurred. Adenosine infusion was terminated in 3 patients (1.5%) because of near syncope or sustained 2:1 atrioventricular block. Electrocardiographic changes occurred in 15 patients (7.3%). Self-assessed scoring after SPECT showed that the patients were very tolerant (74.6% of 177 patients) of adenosine infusion myocardial SPECT. The sensitivity and specificity were 75.0% and 69.7%, respectively. CONCLUSIONS: Adenosine infusion myocardial SPECT is safe and well tolerated in the Japanese population, despite the frequent occurrence of minor adverse reactions.

Changes in escape rhythms several years after radiofrequency ablation of the atrioventricular junction combined with pacemaker implantation.

OBJECTIVE: Escape rhythm is thought to play a considerable role in protection against adverse outcome due to pacemaker malfunction. We studied the escape rhythms in 32 patients with supraventricular tachyarrhythmia refractory to medical therapy who underwent radiofrequency ablation of the atrioventricular junction combined with implantation of a pacemaker. METHODS AND RESULTS: We performed the escape rhythm analysis immediately and 2.6 +/- 1.9 years after the radiofrequency ablation by decreasing the pacing rate. In the initial study, escape rhythms (41 +/- 8 beats/min) were documented in 20 patients (63%). Non-cardiac death occurred in 3 patients with escape rhythm, and cardiac death occurred in I patient without escape rhythm. In the follow-up study, escape rhythms were detected in 22 of 28 patients (79%). Escape rhythm had developed in 6 (55%) of 11 patients who were without escape rhythm initially, while escape rhythm disappeared in 1 of 17 (5.9%) patients who had escape rhythm initially. The changes in escape rhythm were not related to QRS width of the intrinsic beat. There was no correlation between the number of radiofrequency applications or the ratio between atrial and ventricular electrocardiogram voltages of radiofrequency applications and the development of escape rhythms. CONCLUSIONS: The present long-term follow-up study demonstrated that the emergence of an escape rhythm increased several years after ablation, but was unrelated to procedural factors. There are, however, certain patients in whom the disappearance of escape rhythms occur. The evaluation of escape rhythms is thus necessary to determine the risk associated with pacemaker failure.

Coronary pressure measurement to determine treatment strategy for equivocal left main coronary artery lesions.

It is often hard to select a treatment strategy for equivocal left main coronary artery (LMCA) disease. We investigated the usefulness of coronary pressure (CP) measurement for determining the treatment strategy in intermediate LMCA disease. We measured CP in 15 consecutive patients with equivocal LMCA disease (age 67.6 +/- 7.5 years, 14 males). Myocardial fractional flow reserve (FFRmyo) was obtained as the ratio of CP distal to the lesion/aortic pressure under maximal coronary dilation. Patients with FFRmyo > or = 0.75 and <0.75 received medical therapy and coronary artery bypass grafting (CABG), respectively, and were followed up for 32.5 +/- 9.7 (20-47) months. Eight patients received medical therapy and 7 patients underwent CABG in accordance with the FFRmyo criteria noted above. FFRmyo of the LMCA was 0.91 +/- 0.01 and 0.61 +/- 0.03 in patients who received medical and surgical therapy, respectively. Neither reference vessel diameter, minimal lumen diameter, nor percent diameter stenosis was significantly different between patients who received medical and surgical therapy. During the follow-up period, no patients with medical therapy showed symptoms due to the LMCA lesion. Similarly, 5 of 7 patients with CABG showed improvement of symptoms and the remaining 2 patients were hospitalized with congestive heart failure. No cardiac death was recorded in the patients with medical or surgical therapy. In conclusion, the present results clearly demonstrated that CP is clinically useful for determining the treatment strategy for equivocal LMCA lesions but coronary angiography is not.