Trend in Age at the Initial Pacemaker Implantation in Patients With Bradyarrhythmia　- A 50-Year Analysis (1970-2019) in Japan.

BACKGROUND: This study investigated whether the age of patients undergoing pacemaker implantation is increasing.Methods and Results: This study retrospectively reviewed the consecutive cases of 3,582 patients who underwent an initial pacemaker implantation at our hospitals because of symptomatic bradyarrhythmias between 1970 and 2019. The exclusion criteria were: patients with AV block due to cardiac surgery or AV junction ablation, and patients aged <20 years. The patients were divided into 5×10-year groups: those treated in the 1970s (1970-1979), 1980s (1980-1989), 1990s (1990-1999), 2000s (2000-2009), and 2010s (2010-2019). A total of 3,395 patients satisfied the study criteria. The average age at which the patients underwent a first pacemaker implantation increased across the 10-year periods: 63.7±13.2 years in the 1970s, 66.2±12.6 years (1980s), 69.1±12.4 years (1990s), 72.0±11.1 years (2000s), and 75.8±10.0 years (2010s) and advanced significantly in the 1990s, 2000s, and 2010s compared to the 1970s (all P<0.001). The ratio of patients aged ≥80 and ≥90 years increased from 10.6% and 0% in the 1970 s to 38.2% (P<0.001) and 5.2% (P= 0.017) in the 2010s, respectively. CONCLUSIONS: The average age at initial pacemaker implantation increased by 12.1 years over the last 50 years in Japan. In particular, the ratios of ≥80 and ≥90 years as the patients age increased significantly.

A Japanese case of familial cardiac myxoma associated with a mutation of the PRKAR1alpha gene.

Familial cardiac myxoma is inherited as an autosomal dominant syndrome. Here, we report a Japanese case of familial cardiac myxoma identified as a genetic abnormality. The mother experienced multiple recurrence of tumors in the left atrium and left ventricle 40 months after surgical resection of a left atrial myxoma. All recurrent tumors were successfully resected. Her daughter also had a solitary myxoma in the left atrium, but she had no recurrence after the operation. Both patients had lentigines in their face but no endocrine abnormality. Molecular genetic analysis demonstrated involvement of a mutation in the PRKAR1alpha gene.

Vasovagal response induced by a low dose of isoproterenol infusion before tilting-up.

A 56 year-old man was referred to hospital for evaluation of syncopal episodes. During head-up tilt testing, his symptom was reproduced, associated with bradycardia and hypotension, by a low dose of isoproterenol (0.02 microg. kg (-1). min(-1)) infusion in the supine position before tilting-up. Isoproterenol infusion can provoke a vasovagal response without tilting. Careful observation of the patient's hemodynamics is mandatory not only during tilting, but also in the supine position before tilting-up.

Cardiac hemangioma: a report of two cases and review of the literature.

Cardiac hemangioma is extremely rare. We encountered two patients with cardiac hemangioma detected by thoracic echocardiography during a medical checkup. In the first case, transthoracic echocardiography revealed a pedunculated tumor in the left ventricle. Selective left coronary angiography demonstrated that the main feeding artery of the tumor arose from the third diagonal branch of the left anterior descending coronary artery. In the second case, thoracic and transesophageal echocardiography showed an oval tumor arising from the right atrium. Both tumors were successfully resected. Histopathological examination revealed that one of the tumors was a capillary hemangioma and the other was a mixed capillary and cavernous hemangioma. After operation, both patients had an uneventful recovery without any complications.

Superior vena cava syndrome due to fibrosing mediastinitis histologically identical to xanthogranulomatous pyelonephritis.

We present herein a case of superior vena cava (SVC) syndrome caused by localized fibrosing mediastinitis (FM), which had histological features similar to xanthogranulomatous pyelonephritis (XGP). A 63-year-old woman presented with facial swelling 5 months after undergoing right nephrectomy for XGP. Radiologic investigations of the chest confirmed the presence of SVC obstruction due to an intraluminal tumor. The histological features of the tumor were consistent with those of FM and were very similar to those of XGP. Although the pathogenesis of neither FM nor XGP is known, some pathogenic process of FM and XGP may be the same.

What is the optimal increase in resting heart rate with low dose isoproterenol infusion for tilt-induced vasovagal response?

Isoproterenol is widely used as a provocative medium for vasovagal responses during tilt testing. Dose of isoproterenol infusion is generally titrated empirically by increase in resting heart rate before tilt up. To determine the optimal increase in resting heart rate with isoproterenol for tilt-induced vasovagal responses, we studied 97 consecutive patients with unexplained syncope. After the end of a negative baseline tilt (80 degrees for 30 min), the isoproterenol tilt was performed using one of two protocols: two-stage isoproterenol-tilt protocol, with doses of 0.01 and 0.02 microg/kg per min for 10 min each, or one-stage isoproterenol-tilt protocol, with a dose of 1 or 2 microg/min for 10 min. The resting heart rate increase was defined as a percentage increase in the resting heart rate after isoproterenol infusion, compared to the baseline heart rate before the tilt test. In 117 tilt procedures, 28 (93%) of the 30 positive responses occurred with a resting heart rate increase of > or = 21%. With the resting heart rate increase of 60 and 100%, 18 (60%) and 27 (90%) positive responses were observed, respectively. In conclusion, the minimum resting heart rate increase of > or = 21% was required to provoke a vasovagal response during subsequent isoproterenol-tilt (80 degrees for 10 min). Preferably, heart rate should be increased to 60-100% by isoproterenol titration before tilting.