Shinya Nishizawa

Circadian, weekly, and seasonal mortality variations in out-of-hospital cardiac arrest in Japan: analysis from AMI-Kyoto Multicenter Risk Study database.

BACKGROUND Several studies have reported circadian, weekly, and seasonal variations in the rates of out-of-hospital cardiac arrest (OHCA). However, variations in the mortality of OHCA are not well known. METHODS AND RESULTS We investigated the 1396 consecutive cases of OHCA with cardiac etiology between October 2004 and September 2008. There were 2 peaks in the occurrence of OHCA in early morning and late evening. There was a weekly pattern with an increased incidence on Mondays. We found a significant seasonal variation in the frequency of events, with a maximum during winter. There was a trend of reduced mortality in warmest 3 months, especially among a subgroup of ventricular fibrillation/pulseless ventricular tachycardia with arrest witnessed. CONCLUSION The present analyses demonstrated circadian, weekly and seasonal variations in the occurrence, and a seasonal variation in mortality in OHCA. Changes in temperature might influence the severity of OHCA and change the rate of success of cardiopulmonary resuscitation.

Lethal arrhythmia and corticosteroid insufficiency

We describe a case of isolated adrenocorticotropic hormone deficiency that showed ventricular fibrillation associated with QT prolongation. A 72-year-old man was admitted because of consciousness disorder caused by severe hypoglycemia. On the second hospital day, QT intervals were unexpectedly prolonged and ventricular fibrillation occurred. Electrical defibrillation was performed and restored hemodynamically stable condition without neurologic deficits. He was diagnosed with endocrine tests as having isolated adrenocorticotropic hormone deficiency. QT prolongation was improved after hydrocortisone replacement therapy. We considered the QT prolongation was caused by corticosteroid insufficiency. We should be aware that corticosteroid insufficiency may provoke QT prolongation responsible for sudden cardiac death.

The Increased Mortality from Witnessed Out-of-Hospital Cardiac Arrest in the Home

Abstract Background. Research in 2008 demonstrated that the majority of out-of-hospital cardiac arrests (OHCAs) occur in the home, and many important characteristics differ between private and public locations. However, the influence of the location of collapse on survival from OHCA is not well understood. Furthermore, most of the reports have been from Western countries; there is little research from Asia that differentiates the conditions of OHCA. Objective. To investigate the influence of the location of collapse on being discharged alive from OHCA and whether the location of collapse is also an independent predictor of survival from OHCA in Japan. Methods. We analyzed 463 consecutive cases of witnessed OHCA with cardiac etiology that occurred between October 2004 and September 2008 in Japan. We investigated the characteristics of OHCA patients who collapsed in private and public locations, and assessed the influence of the location of collapse on survival from OHCA. Results. Patients who collapsed outside the home were younger, more likely to be male, more likely to receive bystander cardiopulmonary resuscitation (CPR), and more likely to have ventricular fibrillation (VF)/pulseless ventricular tachycardia (VT) and had a shorter time interval between collapse and 9-1-1 call than patients who collapsed in the home. Mortality was significantly higher in the group who collapsed in the home. The independent influence of the location of collapse was eliminated by additional adjustment for time interval from collapse to 9-1-1 call, age, bystander CPR, and initial cardiac rhythm. Finally, VF/pulseless VT as the initial rhythm and bystander CPR were independently associated with the patients being discharged alive; the location of collapse was not an independently associated variable. Conclusions. The present analysis demonstrated that there were significant differences in survival between groups of patients who suffered from cardiac arrest inside and outside the home in Japan. The outside-the-home group had a higher rate of survival from OHCA; however, the location of collapse was not an independent predictor of survival from OHCA. Education of the families of high-risk patients in placing a rapid emergency call and performing effective CPR might be needed to improve survival from cardiac arrest in the home.

Spontaneous pericardial hematoma with familial amyloid polyneuropathy

There are more than a few risks of hemorrhage complication in patients with amyloidosis. Although most cases with amyloidosis exhibit minor bleeding manifestations, they can be occasionally associated with life-threatening problems. To our knowledge, there are only a few cases of spontaneous pericardial hematoma associated with amyloidosis. We here report a patient who suddenly died of cardiac tamponade with massive pericardial hematoma 7 years after the diagnosis of familial amyloid polyneuropathy (FAP). A 69-year-old female with FAP with cardiogenic shock was admitted to our emergency room. Although she previously underwent permanent pacemaker implantation for atrial fibrillation with slow ventricular response, electrocardiogram showed a critical pacing failure. Emergent telemetry check revealed a sudden extreme increase of pacing capture threshold in the right ventricle. Maximum pacing voltage could not improve the critical condition, and she died 7 h after arrival. Autopsy showed a massive pericardial hematoma in the right ventricular free wall, and microscopic examination revealed typical amyloid deposition in the arterial wall of the pericardium. In this case, it is assumed that a sudden rupture of fragile pericardial vessels with amyloid deposition led to the lethal pericardial hematoma.