The conduction system in patients with a prolonged QT interval

Abstract

The conduction system and the myocardium of five patients with Romano-Ward syndrome and one patient with the Jervell and Lange-Nielsen syndrome were studied to determine the cause of the prolonged QT interval. The patients were 9 and 15 months and 2, 5 and 19 years of age, respectively. All had a prolonged QTc interval. A sixth patient was a 16 year old girl who died suddenly; several members of her family had a prolonged QT interval. The only common finding in the conduction system in all cases was marked fatty infiltration in the approaches to the atrioventricular (AV) node. In four, the AV bundle was lobulated, with loop formation in one. In four, the AV bundle and bundle branches showed fibrosis. The ventricular myocardium in all cases was chronically inflamed. In two cases, the AV node was partially embedded in the central fibrous body. It is not clear how these changes are related to the disturbance in the repolarization process and the prolongation of the QT interval. However, it is interesting that all patients had an abnormality in the conduction system.

Crib death: further support for the concept of fatal cardiac electrical instability as the final common pathway

“…This is in contrast with other authors who considered instead the autopsy very important in every case of sudden death in infancy [67,88,94,107,108,114].…”

“…Matturri et al [67] found AV node dualism present in two cases of crib death (2.89%), and in none of control cases, while His bundle dualism was present in 2.89% of crib death and in 4.16% of explained death cases. Bharati et al [88] described a case of distinct AV node-like structure on the parietal wall of the right atrium in a patient with a history of paroxysmal supraventricular tachycardia.…”

Prevalence of QT interval prolongation in inflammatory bowel disease

“…In previous studies involving patients with IBD, cardiac complications, such as CAD, arrhythmias, myocarditis, pericarditis, heart blocks, have been associated with chronic inflammation (5,10,11). In our study, the risk factors except for BMI were similar in patients having IBD with and without prolonged QTc interval.…”

“…Factors influencing QT interval prolongation includes genetic abnormality, medications (e.g., antiarrhythmics, antihistaminics, psychotropics, and antibiotics), electrolyte abnormalities (i.e., hypokalemia, hypocalcemia, or hypomagnesemia), and myocardial ischemia (1,5). Bharati et al (5) also found that QT interval prolongation was associated with chronic inflammation of the ventricular myocardium.…”

Compound Heterozygosity for Mutations (W156X and R225W) in SCN5A Associated With Severe Cardiac Conduction Disturbances and Degenerative Changes in the Conduction System

“…These observations, taken together with the fact that autopsies from patients with LQTS have revealed structural changes, in particular in the conduction system, 31 and the fact that an ion channel (hRyR2) defect has been found to underlie one form of arrhythmogenic right ventricular dysplasia (ARVD2), 32 begs the consideration that ion channel defects may result in morphological changes and some form of cardiomyopathy.…”