The pathological investigation of sudden cardiac death

The coronary artery calcification severity on postmortem CT could be a clue for the diagnosis of sudden cardiac death

About two-thirds of sudden deaths are sudden cardiac deaths (SCD), and ischemic heart disease (IHD) accounts for 60% of these. Although an autopsy needs to be performed to prove SCD, the forensic autopsy rate is very low in Japan. To diagnose the cause of death, postmortem computed tomography (PMCT) is often performed. Because coronary artery calcification (CAC) is a risk factor in cardiac diseases such as IHD and its severity can be evaluated with CT, we examined its ability to diagnose SCD. We collected 104 autopsy cases with CT scans. On the basis of the autopsy report, we separated the cases into two groups: SCD suspected as the cause of death and SCD not suspected. We calculated each CAC severity with the Agatston score from the CT images. Cases with Agatston scores of more than 400 were labeled as severe. The relationship between SCD and CAC severity was confirmed with Fisher's exact test (p < 0.05). The sensitivity and specificity of CAC severity for SCD were 20.3% and 97.5%, respectively, and the positive likelihood ratio was 8.1. Severe CAC can increase the probability of SCD. In cases in which only PMCT can be performed, this finding can be helpful for diagnosing SCD.

Ventricular arrhythmia and sudden cardiac death in young Leonbergers

INTRODUCTION

To describe unexpected sudden cardiac death (SCD) in young Leonbergers (<3 years) and to review the circumstances before death and necropsy findings; to prospectively evaluate the presence of possible arrhythmias in young Leonbergers; and to examine pedigrees for determining potential modes of inheritance.

ANIMALS

Postmortem evaluations included 21 Leonbergers. Clinical evaluation consisted of 46 apparently healthy Leonbergers with and without a close family history of SCD.

MATERIALS AND METHODS

Necropsy reports were reviewed retrospectively. Prospective clinical evaluation included physical examination, 5-min electrocardiogram, 24-h Holter, echocardiography, and laboratory tests. Pedigree data were examined for mode of inheritance.

RESULTS

Based on necropsy reports, SCD occurred at a median age of 12 months (range, 2.0-32.0 months) without any previous clinical signs and usually in rest. No evidence of structural cardiac disease was found; arrhythmia-related death was suspected. Clinical evaluation and 24-h Holter showed ventricular arrhythmia (VA) in 14 apparently healthy Leonbergers (median age, 18 months; range, 12-42 months). Severity of VA varied from infrequent couplets/triplets to frequent complexity (couplets, triplets, nonsustained ventricular tachycardias,VTs) characterized by polymorphology. During follow-up, two dogs with polymorphic VT died. Although breed specificity and high prevalence indicate a heritable disease, based on available pedigree data, the mode of inheritance could not be determined.

CONCLUSIONS

Sudden cardiac death in young Leonbergers is associated with malignant VA characterized by complexity and polymorphic nature. Diagnosis is based on 24-h Holter monitoring. Pedigree analysis suggests that the arrhythmia is familial.