van Amerongen, Evita A. (2020) Heart Rate Reduction as a Prognosticator of Arrhythmia in Asymptomatic Genotype-Confirmed, Phenotype Negative Catecholaminergic Polymorphic Ventricular Tachycardia. thesis, Medicine.
Full text available on request.Abstract
Background Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare, hereditary electrical heart disease and, if left untreated, highly lethal especially in young children and adults. The group of asymptomatic, pathogenic RYR2-mutation carriers is becoming bigger, but little is known about their clinical course and risk stratification in these patients is ill defined. Heart rate reduction (HRR) after exercise, caused by vagal reflexes, may have an influence on the development of severe arrhythmia. Aims To identify the clinical course of asymptomatic RYR2-mutation carriers and to evaluate the risk of developing arrhythmia, predominantly looking at HRR after exercise on exercise stress test (EST). Methods In this retrospective observational cohort study, we included asymptomatic, RYR2-genotype confirmed mutation carriers identified through family cascade screening, with first EST off anti-arrhythmatic drugs. Clinical course was evaluated as time-to-event between two phenotype groups. The phenotype negative subgroup was used to evaluate risk factors on developing arrhythmia. HRR was calculated as maximum heart rate (HRmax) minus heart rate at 1 or 2 minutes recovery, in patients who reached >85% of maximum predicted heart rate. Results In the first analysis, we included 132 patients: 82 in the phenotype negative group (BPT-, median age 23), 50 in the phenotype positive group (BPT+, median age 38). Four events occurred in the BPT- group (4,9%) and 2 in the BPT+ group (4%). There was no difference in clinical course (log-rank: p = 0.667). ΔHRR was greater (p = 0,032) and both heart rates after 1 (p = 0,009) and 2 minutes (p = 0,019) were lower in the arrhythmia group. Conclusions Having a high ΔHRR1 on the first EST is a possible new risk stratification tool for development of arrhythmia in asymptomatic CPVT patients. We found no difference in clinical course between the two phenotype groups.
| Item Type: | Thesis (UNSPECIFIED) |
|---|---|
| Supervisor name: | Wilde (MD, PhD), Prof. Dr. A.A.M and van der Werf (MD, PhD), Dr. C. and Peltenburg (MD, PhD candidate), Drs. P.J. and van den Berg (MD, PhD), Prof. Dr. Maarten |
| Faculty: | Medical Sciences |
| Date Deposited: | 01 Aug 2023 11:09 |
| Last Modified: | 01 Aug 2023 11:09 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/3606 |
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