Ryosuke Takeuchi

Endless loop tachycardia below the upper tracking rate of a pacemaker: A case report

An 82‐year‐old female with a history of hypertrophic cardiomyopathy (HCM), sick sinus syndrome (SSS), and an implanted DDD pacemaker was admitted to our hospital for congestive heart failure caused by rapid atrial fibrillation. After administration of amiodarone, atrial fibrillation (AF) became atrial flutter (AFL). Electrophysiological investigation revealed counterclockwise AFL. Catheter ablation of the cavotricuspid isthmus was performed. Burst pacing from the coronary sinus ostium to confirm the block line of the isthmus induced rapid, regular, ventricular pacing at a rate of 110 bpm. The differential diagnosis of this tachycardia included ectopic atrial tachycardia and pacemaker‐mediated, endless loop tachycardia (ELT). We diagnosed this arrhythmia as ELT, because temporary reprogramming of the pacemaker mode from DDD to VVI terminated the tachycardia. In this patient, pacing parameters favored ELT (long atrioventricular delay [AVD] and short postventricular atrial refractory period [PVARP]), and atrioventricular and ventriculoatrial conduction time was prolonged as a result of amiodarone administration.

Right ventricular infarction caused by tricuspid ring annuloplasty.

Injury to the right coronary artery (RCA) is a rare complication of tricuspid annuloplasty. We report a patient who developed right ventricular (RV) infarction, because of tricuspid annuloplasty, and review management options.

A case of ventricular septal rupture associated with major septal branch occlusion after percutaneous coronary intervention

A 67-year-old man underwent elective percutaneous coronary intervention (PCI) of the left anterior descending artery. The major septal branch became occluded during coronary stenting. The patient developed dyspnea 19 days later. Chest radiography revealed lung congestion and a pleural effusion. Transthoracic echocardiography revealed a basal ventricular septal rupture. Emergency coronary angiography did not reveal any in-stent restenosis, and the major septal branch remained occluded. Therefore, the patient underwent closure of the ventricular septal rupture. The postoperative period was uneventful, and he was discharged 29 days after the operation. Septal branch occlusion due to coronary stenting occasionally occurs during routine PCI for which recanalization is sometimes not attempted. However, this case demonstrates that occluded septal branches, although rare, may cause serious complications. <Learning objective: Rupture of the ventricular septum, a complication of acute myocardial infarction, is usually observed in the setting of acute myocardial infarction associated with major coronary artery occlusion. However, ventricular septal rupture associated with side branch occlusion due to coronary stenting for stable angina pectoris is uncommon. Awareness of this rare complication is useful during routine percutaneous coronary intervention.>.

Diagnostic value of 3T whole heart coronary magnetic resonance angiography (MRA) without contrast medium

Methods From May 1 to September 6 in 2012, 31 consecutive patients received whole heart coronary MRA without contrast medium in 3T MRI scanner (Ingenia 3.0T, Philips Healthcare). 26 patients (84%) had sufficient quality to analyze. In these, 21 patients (16 men; mean age 69 years) received coronary angiography within 1 month of MRA. In MRA, coronary arteries were segmented to proximal, mid, distal RCA (segment 1, 2, 3), LMT (segment 5), proximal, mid, distal LAD (segment 6, 7, 8), and proximal, distal LCX (segment 11, 13). In coronary angiography, a stenosis of over 50% was defined to be significant. The segments after stent implantation were excluded.