High-degree atrioventricular (AV) blocks that emerge after transcatheter aortic valve replacement (TAVR) have links to certain patterns in the electrocardiogram (ECG), a Swiss study suggested. AV block occurred in 6.7% of patients and up to 8 days after TAVR. Delayed high-degree AV block was more common in men (odds ratio [OR] 2.4, 95% CI 1.3-4.5) and patients with conduction disorders — left or right bundle branch blocks — after TAVR (OR 10.8, 95% CI 4.6-25.5). Delayed high-degree AV block was not seen in those in sinus rhythm with no conduction disorders after TAVR and those with had had a stable ECG for at least 2 days, Stefan Toggweiler, MD, of Switzerland’s Heart Center Lucerne, and colleagues reported online in JACC: Cardiovascular Interventions. Those with atrial fibrillation and no other conduction disorders also had low odds of delayed AV block (1%). These patients may not require telemetry monitoring, Toggweiler’s group suggested, though “all other patients should be monitored until the ECG remains stable for at least 2 days.” “As some patients may not require telemetry at all, the present study showed that the ECG recorded immediately after TAVR was able to identify such patients,” they added. Toggweiler and colleagues assessed the records of 1,064 patients who underwent TAVR at three centers in their observational study. The findings provide “the rationale for a new and simplified perspective on the management of rhythm monitoring after TAVR,” Marina Urena, MD, of Bichat-Claude Bernard Hospital in Paris, and Josep Rodés-Cabau, MD, of Quebec Heart & Lung Institute in Canada, wrote in an accompanying editorial. But “while minimizing the post-procedural care burden and reducing the length of hospital stay are important objectives in TAVR, this should never be at the expense of decreasing safety,” they cautioned. Urena and Rodés-Cabau questioned whether the results can be applied to TAVR with new-generation devices or to a larger population. “Up to 72 hours of continuous ECG monitoring post-procedure is currently recommended in order to detect late arrhythmic events. Nonetheless, no strong evidence supports this cutoff value and the minimum duration of continuous ECG monitoring required after TAVR remains largely unknown,” they wrote. Disclosures Toggweiler reported serving as a proctor to Symetis and receiving speaker fees from Edwards Lifesciences, Medtronic, and Symetis. Urena declared no relevant conflicts of interest. Rodés-Cabau disclosed receiving research grants from Edwards Lifesciences and Medtronic.