Tomomi Abe

Effect on treadmill exercise capacity, myocardial ischemia, and left ventricular function as a result of repeated whole-body periodic acceleration with heparin pretreatment in patients with angina pectoris and mild left ventricular dysfunction.

Whole-body periodic acceleration (WBPA) has been developed as a passive exercise device capable of improving endothelial function by applying pulsatile shear stress to vascular endothelium. We hypothesized that treatment with WBPA improves exercise capacity, myocardial ischemia, and left ventricular (LV) function because of increased coronary and peripheral vasodilatory reserves in patients with angina. Twenty-six patients with angina who were not indicated for percutaneous coronary intervention and/or coronary artery bypass grafting were randomly assigned to remain sedentary (sedentary group) or undergo 20 sessions of WBPA with the motion platform for 4 weeks (WBPA group) in addition to conventional medical treatment. WBPA was applied at 2 to 3 Hz and approximately ±2.2 m/s² for 45 minutes. We repeated the symptom-limited treadmill exercise test and adenosine sestamibi myocardial scintigraphy. In the WBPA group, the exercise time until 0.1-mV ST-segment depression increased by 53% (p <0.01) and the double product at 0.1-mV ST-segment depression by 23% (p <0.001). Severity score of myocardial scintigraphy during adenosine infusion decreased from 20 ± 10 to 14 ± 8 (p <0.001) and severity score at rest also decreased from 13 ± 10 to 8 ± 10 (p <0.01). On scintigraphic images at rest, LV end-diastolic volume index decreased by 18% (p <0.01) with an augmentation of LV ejection fraction from 50 ± 16% to 55 ± 16% (p <0.01). In contrast, all studied parameters remained unchanged in the sedentary group. In conclusion, treatment with WBPA for patients with angina ameliorates exercise capacity, myocardial ischemia, and LV function.

Automatic switching between the AAI and the DDD algorithm can prevent repetitive non-reentrant ventriculoatrial synchrony

A 67‐year‐old man with non‐obstructive hypertrophic cardiomyopathy had received an implantable cardioverter‐defibrillator (ICD) for an unstable, sustained ventricular tachycardia (VT) induced by programmed stimulation during an electrophysiological study 5 years earlier. An intracardiac electrogram recorded by the ICD revealed repetitive, non‐reentrant ventriculoatrial synchrony (RNRVAS) associated with hypotension. Electrophysiologic and hemodynamic studies indicated that RNRVAS was induced and reproducibly termed by a single ventricular extrastimulus from the right ventricular apex. Following attainment of the elective replacement indicator, we replaced the ICD with another having managed ventricular pacing, which automatically switched AAI and DDD, thereby avoiding unnecessary ventricular pacing. Thus far, the patient has not experienced further RNRVAS. Thus, we believe that automatic switching between AAI and DDD can prevent RNRVAS.

High-risk transseptal puncture in a patient with a “pancake” deformity in the left atrium caused by descending aorta displacement

Catheter ablation via the transseptal approach has recently become a widely performed technique for treating atrial fibrillation (AF). However, fluoroscopic imaging provides limited anatomic guidance for the left atrial structure. We describe the case of a 78‐year‐old man who was referred to our hospital for pulmonary vein isolation for symptomatic paroxysmal AF. He had a history of pulmonary tuberculosis for which he had undergone a right upper lobectomy. A “pancake” deformity of the left atrium (LA) was observed using 64‐slice multislice computed tomography. We performed a transseptal puncture by using real‐time three‐dimensional transesophageal echocardiography (RT3D‐TEE) in combination with fluoroscopic imaging, without any complications. Although transseptal puncture can be performed without echocardiographic guidance in most patients, in our patient, RT3D‐TEE proved to be a very helpful imaging technique to access the LA.

Late Gadolinium Enhancement and Signal Average Electrocardiogram for Predicting Ventricular Tachyarrhythmia

Late gadolinium enhancement (LGE) during cardiac magnetic resonance (CMR) is associated with the prevalence of ventricular tachycardia/ventricular fibrillation (VT/VF). Signal average electrocardiogram (SAECG) is also relevant to VT/VF. The purpose of this study was to investigate the clinical significance of LGE and SAECG for patients with organic heart disease. We studied 150 patients with organic heart disease who performed CMR from 2006 to 2011. We examined them about LGE and SAECG for incidence of VT/VF. Their mean age was 62.9 years old, their mean left ventricular ejection fraction was 45.3%, and mean brain natriuretic peptide was 440 pg/ml. Their underlying heart disease were ischemic heart disease (IHD, 46 patients), dilated cardiomyopathy (38 patients), hypertrophic cardiomyopathy (HCM, 38 patients), and others. Ninety-four patients showed LGE in CMR, and 26 patients experienced VT/VF during follow-up of 13.4±9.4 months. In IHD patients, incidence of VT/VF was higher in patients with positive SAECG than patients with negative SAECG (37% vs 9%, p<0.05). In HCM patients, VT/VF occurred more frequently in patients with LGE than patients without LGE (24% vs 0%, p<0.05). In IHD, SAECG is more valuable in predicting tachyarrhythmia event. On the other hand, in HCM, LGE offers more useful information.

AV Nodal Reentrant Tachycardia in a Patient with Persistent Left Superior Vena Cava: Distinction between AV Nodal Versus Atrial Reentry

A 75‐year‐old male presented with palpitation on exertion. He suffered from frequent tachycardia attacks. His 12‐leads electrocardiogram showed irregular cycle lengths (400–550 ms) of tachycardia with occasional 2:1 atrioventricular conduction (thus AV reentry was excluded). He had a complex anatomy of persistent left superior vena cava (PLSVC)/ enlarged coronary sinus (CS). The activation map in a 3‐dimensional CARTO system (Biosense‐Webster, USA) was merged with the multi‐detector computed tomography image and revealed that the tachycardia spread centrifugally from the junction between the PLSVC and enlarged CS. However, delivery of radio frequency (RF) energy to the earliest atrial activation site did not affect the tachycardia. Finally, the tachycardia was diagnosed as a fast/ slow type atrioventricular nodal reentrant tachycardia (AVNRT) because the tachycardia was cured only after the anterograde/retrograde AV conduction was disturbed by the application of RF energy to the posteroseptal perimitral area, possibly due to the injury to the AV node.