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Although it has been reported that endotoxin-induced expression of Nox1 in the heart contributes to apoptosis in cardiomyocytes, functional role of Nox1 at the physiological expression level has not been elucidated. The aim of this study was to clarify the role of Nox1 under a hypoxic condition using wild-type (WT, Nox1(+/Y)) and Nox1-deficient (Nox1(-/Y)) mice. ECG recordings from anesthetized mice revealed that Nox1(-/Y) mice were more sensitive to hypoxia, resulting in bradycardia, compared to WT mice. Atrial and ventricular electrocardiograms recorded from Langendorff-perfused hearts revealed that hypoxic perfusion more rapidly decreased heart rate in Nox1(-/Y) hearts compared with WT hearts. Sinus node recovery times measured under a hypoxic condition were prolonged more markedly in the Nox1(-/Y) hearts. Sinoatrial node dysfunction of Nox1(-/Y) hearts during hypoxia was ameriolated by the pre-treatment with the Ca(2+) channel blocker nifedipine or the K(+) channel opener pinacidil. Spontaneous action potentials were recorded from enzymatically-isolated sinoatrial node (SAN) cells under a hypoxic condition. There was no significant difference in the elapsed times from the commencement of hypoxia to asystole between WT and Nox1(-/Y) SAN cells. These findings suggest that Nox1 may have a protective effect against hypoxia-induced SAN dysfunction.

Background Implantable cardioverter-defibrillator (ICD) is recommended for secondary prevention in patients with coronary spastic angina and aborted sudden cardiac death. The effectiveness of subcutaneous ICD (S-ICD) for patients with coronary artery spastic angina is controversial. Case summary A 54-year-old man presented with ventricular fibrillation. Emergent coronary angiography showed diffuse narrowing of the coronary arteries that was reversible with isosorbide dinitrate. He was diagnosed with coronary spastic angina. S-ICD was implanted after the administration of a calcium-channel blocker and nicorandil. Seven months after the implantation, he collapsed again due to sinus node dysfunction and atrioventricular block caused by cardiac ischaemia. He developed cardiac arrest at both admissions. Six hours after the admission, electrocardiogram showed transient right bundle branch block. Inappropriate shocks were delivered because of low R-wave amplitude and T-wave oversense. S-ICD was replaced with a transvenous device in order to manage these two arrhythmias and inappropriate shocks. Discussion Patients with coronary artery spasm and aborted sudden cardiac death are candidates for implantation of S-ICD, but there are risks of bradycardia and inappropriate shocks in other ischaemic events.

SummaryPrimary percutaneous coronary intervention (PCI) for ST-elevated myocardial infarction (STEMI) results in dramatically improved clinical outcomes when performed in a timely manner. Although guidelines for STEMI patients recommend PCI should be performed by experienced operators with acceptable PCI volume, cardiologists in a local area must perform primary PCI at their own hospitals. This study evaluated the effects of cardiologist experience on outcomes for STEMI patients in a local area in Japan.Between April 2007 and March 2010, 140 consecutive STEMI patients were admitted to our hospital and 121 of these patients received primary PCI. STEMI patients undergoing primary PCI were divided into two groups according to the operator's experience as a cardiologist. We retrospectively analyzed their clinical backgrounds, PCI findings, in-hospital outcomes, and drug administration at discharge.There were no significant differences in any clinical characteristics, angiographic findings, or PCI procedures between the two groups. Clinical outcomes of the two groups were similar, except for the length of hospital stay (21.1 ± 5.8 versus 15.5 ± 9.7; P = 0.0255). The frequency of administration of drugs such as β-blockers (59.1% versus 34.0%; P = 0.0086), aldosterone blockade (10.4% versus 25.5%; P = 0.0334), and nicorandil (76.1% versus 25.5%; P = < 0.0001) was different between the two groups.The clinical outcomes of STEMI patients in this study were satisfactory and almost equivalent when compared according to the experience of the attending cardiologist. The present findings suggest the important clinical implication that younger cardiologists who have experienced PCI procedures to a certain extent can safely perform primary PCI and contribute to better prognoses of STEMI patients. (Int Heart J 2011; 52: 127-130)

These findings indicate that patients with ET>12 h have a less severe condition and less frequently receive primary PCI compared with patients with ET≤12 h. Although primary PCI is often performed for these patients irrespective of the severity of heart failure, no preferable effect of primary PCI on the in-hospital mortality is demonstrated. In contrary, practice of primary PCI is a significant negative predictor of in-hospital mortality for patients with ET≤12 h.

Pacemaker implantation (PMI) is a standard treatment for symptomatic bradyarrhythmia. Pneumothorax, aortic perforation, and pericardial effusion were reported as major complications of this procedure [1,2]. A cohort study in Denmark found that the incidence was 9.5% of 5918 patients who were implanted with a cardiac implantable electronic device (CIED), among which cardiac perforation was 0.6%, the male to female ratio was 1.1% vs 0.4% [2]. In the study of the recipients of permanent pacemakers from 2008 to 2012 in the USA, cardiac tamponade occurred in 2595 cases, which was 0.28% for the implantation of 922,549 patients [3]. Many cases can be managed conservatively with drainage or lead revision, but sometimes surgical intervention is required. We report a rare case of cardiac tamponade due to injury of the coronary artery by an atrial screw-in lead. Case reportA 74-year-old man visited the emergency room because of syncope. He was diagnosed with bradycardia tachycardia syndrome two years previously with presyncope. At that time, he took no drug that could cause bradycardia. Ambulatory electrocardiographic monitoring revealed maximum of 5 sec sinus arrest after the termination of atrial fibrillation, but he refused PMI. At

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A 49-year-old woman complaining of anterior chest pain underwent emergent coronary angiogram and thrombotic obstruction in the proximal left anterior descending artery was discovered. Deployment of a bare metal stent recovered good coronary flow and congestive heart failure was soon relieved. However, on day 3 of hospitalization, chest radiography suddenly showed newly emergent bilateral pulmonary infiltration shadow mimicking congestive heart failure. Chest computed tomography and clinical findings suggested bilateral alveolar hemorrhage. The patient received dual antiplatelet therapy, aspirin 100 mg/day and clopidogrel 75 mg/day and continuous 15,000 U/day heparin infusion, after percutaneous coronary intervention. Therapies that minimize bleeding risk while maintaining an antithrombotic effect are required for patients with acute coronary syndrome (ACS). Due to concern about the increased risk of early stent thrombosis induced by discontinuation of antiplatelet therapy, we continued to administer dual antiplatelet therapy. Pulmonary hemorrhage complicated with ACS without abciximab is a rare clinical entity, and we successfully overcame this potentially life-threatening complication with conservative therapy.