Impact of genetic reclassification on ARVC diagnosis based on the 2010 task force criteria

Introduction

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is an inherited condition, which is associated with potentially life-threatening ventricular arrhythmias in the young. Approximately 60% of patients carry a possibly disease-causing genetic variant.

Purpose

The aim of this study was to investigate the impact of the 2015 American College of Medical Genetics (ACMG) Criteria on ARVC diagnosis based on the 2010 Modified Task Force Criteria (TFC).

Methods

The study included 79 patients from the Swiss ARVC Registry who harbored a genetic variant deemed to be associated with the disease at initial screening, and classified them as definite, borderline or possible ARVC. Every variant found was re-classified on Varsome Genetics, based on the 2015 ACMG Criteria. Clinical information was then assessed at last available follow-up of every patient and ARVC diagnosis was reclassified based on the newest genetic evidence available.

Results

In 42 out of 79 patients (53.2%), genetic variants were reclassified. Out of these, 33 variants (41.8%) were downgraded from pathogenic (P) / likely pathogenic (LP) to either variants of unknown significance (VUS) or benign (B) / likely benign (LB). Three patients (3.8%) were upgraded from VUS / LP to P. Out of the 12 variants initially classified as VUS, 9 (75%) were reclassified as B or LB. Overall, 13 patients (16.5%) were downgraded from their initial diagnosis (11 from definite to borderline and 2 from borderline to possible).

Conclusion

A significant proportion of patients with ARVC diagnosed based on the 2010 TFC were reclassified when the 2015 ACMG Criteria were taken into consideration. These findings may have clinical consequences, particularly for genetic cascade screening of family members of ARVC patients and necessitate reassessment of genetic variants of index patients who were previously diagnosed with ARVC.

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): University Hospital Zurich

[Electrocardiographic changes during stress test in a patient with "Brugada syndrome"]

We report a 28 year old man with the Brugada syndrome characterised by an electrocardiographic pattern of a right bundle branch block and an ST segment elevation in the right precordial leads as well as syncope. During an exercise test, we observed a normalization of the ST segment in V2+ while in the postexercise phase, the ST segment elevation in the right leads was established. This is the first case reported of the Brugada syndrome in Mexico, with spontaneous changes on the EKG masked during exercise and apparent during postexercise phase.

Current status of some zoonoses in Togo

In Togo, livestock represent an important part of the national and subsistence economies. The most prevalent zoonoses documented in Toga are brucellosis, tuberculosis, cysticercosis and rabies. The status of other zoonoses such as toxoplasmosis, giardiasis, cryptosporidiosis and salmonellosis is not known. A national eradication programme has been instigated to reduce the transmission of rabies. Good relations exist between veterinary and health personnel in the field but this level of interaction is absent at district and national level. This has resulted in information not being transferred between the two disciplines and the lack of a national strategy for the eradication of zoonoses in Togo.

[The effectiveness and safety of d,l-sotalol in the ambulatory treatment of atrial fibrillation and flutter]

Data on short and long term efficacy and safety of d,l sotalol in patients with atrial fibrillation or atrial flutter is limited. The aims of this study were to (1) assess the antiarrhythmic efficacy of d,l sotalol maintaining normal sinus rhythm in patients with refractory atrial fibrillation or flutter, (2) evaluate the efficacy of d,l sotalol in preventing recurrences of paroxysmal atrial fibrillation or flutter, (3) evaluate the control of ventricular rate in patients with paroxysmal or refractory atrial fibrillation or flutter unsuccessfully treated with other antiarrhythmic agents, (4) determine predictors of efficacy (5) assess the safety of d,l sotalol in this setting. Two hundred patients with chronic or paroxysmal atrial fibrillation or atrial flutter or both, who had failed one to six previous antiarrhythmic drug trials were treated with d,l sotalol 80 to 440 mg/day orally. Fifty four percent was female, age 47 +/- 16 years (range 7-79), follow up period 7 +/- 7 months (range 1 to 14 months), 79% of patients had the arrhythmia for more than one year. The atrial fibrillation in 37.5% of patients was chronic and paroxysmal in 23.5. The atrial flutter was chronic in 31% of patients and paroxysmal in 8%. Eighty two percent of patients was in functional class I (NYHA) and 82% had cardiac heart disease: left atrial (LA) size 44 +/- 10 mm, right atrial (RA) size 37 +/- 7 mm and left ventricular ejection fraction (LVEF) 58 +/- 8%. Total success was achieved in 58% of patients (atrial fibrillation 40% and 18% in atrial flutter), partial success in 38% (atrial fibrillation in 18% and 20% in atrial flutter) and 4% of patients failure. It was p < 0.07 when compared total success vs partial success among atrial fibrillation and atrial flutter groups. Patients with cardiac heart disease responded worst (p = 0.10) to the drug than those without it, specially if the heart was dilated. We concluded that d,l sotalol has moderate efficacy to convert and maintain normal sinus rhythm, as well as it acts controlling paroxysmal relapses and ventricular heart rate.