Search

This commentary refers to a case report describing dual ventricular responses following a single P-wave, which is an unusual but possibly underdiagnosed phenomenon. The AV node synchronizes atrial and ventricular mechanical functions, acts as an electrical filter protecting the ventricles from high heart rates during atrial fibrillation and flutter and is also a back-up generator if the sinus node fails. Dual AV-nodal pathways are the substrate for the relatively common AV-nodal re-entrant tachycardia (AVNRT), which is curable by ablation. Ablation is also the therapy of choice when dual ventricular responses cause palpitations with or without AVNRT, or in rare cases of continuously impaired ventricular mechanical function.

Early repolarization defined as antero-lateral ST-segment elevation exists in 1-2 % of the general population and has been considered a benign ECG finding for decades. However, early repolarization, defined as infero-lateral J-waves, has in recent studies been associated with an increased - albeit low - risk of sudden and cardiovascular death. This ECG pattern is present in 3-13% of the general population. However, exercise training can induce all types of early repolarization, and the prevalence in the athletic population rises to 20-90%. There is large variability between sports (higher in endurance athletes) and also throughout the season (higher during times of peak fitness). In athletes, early repolarization, regardless of type, is considered benign. In asymptomatic non-athletes, the absolute risk is too low to use this ECG finding in clinical practice. In individuals with J-wave syndrome, on the other hand, ICD implantation should be strongly considered to prevent sudden cardiac death.

Diagnostic coronary angiography and percutaneous coronary interventions (PCI) are rapidly developing fields. In-house thoracic surgery backup is no longer a prerequisite for PCI. The demand for physicians trained in interventional cardiology has created a need to formalise such education. The Swedish societies of cardiology and thoracic radiology have agreed on a policy document establishing the details of this education. It is the responsibility of the tutor to decide when the pupil has achieved adequate skills.

Of 517 emergency room admissions for syncope at four Stockholm hospitals, 36 (7 per cent) were found to be cases of bifascicular block. Of these 36 patients, 34 underwent ambulatory electrocardiography (ECG) in hospital, which showed significant arrhythmia to be present in three cases [high-grade atrioventricular block (n = 2), or sustained ventricular tachycardia (n = 1)]. After a mean follow-up of 32 months, eight more patients had developed high-grade atrioventricular block, and 13 patients had died (eight of them suddenly). It is concluded that patients with bisfascicular block constitute a high-risk category, and would benefit from thorough investigation, including an invasive electrophysiological study, in order to identify those at risk of progression to high-grade atrioventricular block or malignant ventricular arrhythmia.