Polymorphic ventricular tachyarrhythmias are highly lethal arrhythmias. Several types of polymorphic ventricular tachycardia have similar electrocardiographic characteristics but have different modes of therapy. In fact, medications considered the treatment of choice for one form of polymorphic ventricular tachycardia, are contraindicated for the other. Yet confusion about terminology, and thus diagnosis and therapy, continues. We present an in-depth review of the different forms of polymorphic ventricular tachycardia and propose a practical step-by-step approach for distinguishing these malignant arrhythmias.

Aims: Distinctive types of polymorphic ventricular tachycardia (VT) respond differently to different forms of therapy. We therefore performed the present study to define the electrocardiographic characteristics of different forms of polymorphic VT. Methods and results: We studied 190 patients for whom the onset of 305 polymorphic VT events was available. The study group included 87 patients with coronary artery disease who had spontaneous polymorphic VT triggered by short-coupled extrasystoles in the absence of myocardial ischaemia. This group included 32 patients who had a long QT interval but nevertheless had their polymorphic VT triggered by ectopic beats with short coupling interval, a subcategory termed ‘pseudo-torsade de pointes] (TdP). For comparison, we included 50 patients who had ventricular fibrillation (VF) during acute myocardial infarction (‘ischaemic VF’ group) and 53 patients with drug-induced TdP (‘true TdP’ group). The QT of patients with pseudo-TdP was (by definition) longer than that of patients with polymorphic VT and normal QT (QTc 491.4 ± 25.2 ms vs. 447.3 ± 55.6 ms, P < 0.001). However, their QT was significantly shorter than that of patients with true TdP (QTc 564.6 ± 75.6 ms, P < 0.001). Importantly, the coupling interval of the ectopic beat triggering the arrhythmia was just as short during pseudo-TdP as during polymorphic VT with normal QT (359.1 ± 38.1 ms vs. 356.6 ± 39.4 ms, P = 0.467) but was much shorter than during true TdP (581.2 ± 95.3 ms, P < 0.001). Conclusions: The coupling interval helps discriminate between polymorphic VT that occurs despite a long QT interval (pseudo-TdP) and polymorphic arrhythmias striking because of a long QT (true TdP).

Indications for surgery in patients with degenerative mitral regurgitation (DMR) are increasingly liberal in all clinical guidelines but the role of secondary outcome determinants (left atrial volume index ≥60 mL/m², atrial fibrillation, pulmonary artery systolic pressure ≥50 mmHg and moderate to severe tricuspid regurgitation) and their impact on post-operative outcome remain disputed. Whether these secondary outcome markers are just reflective of the DMR severity or intrinsically affect survival after DMR surgery is uncertain and may have critical importance in the management of patients with DMR. To address these gaps of knowledge the present study gathered a large cohort of patients with quantified DMR, accounted for the number of secondary outcome markers and examined their independent impact on survival after surgical correction of the DMR. The Mitral Regurgitation International DAtabase-Quantitative registry includes patients with isolated DMR from centres across North America, Europe, and the Middle East. Patient enrolment extended from January 2003 to January 2020. All patients undergoing mitral valve surgery within 1 year of registry enrolment were selected. A total of 2276 patients [65 (55–73) years, 32% male] across five centres met study eligibility criteria. Over a median follow-up of 5.6 (3.6 to 8.7) years, 278 patients (12.2%) died. In a comprehensive multivariable Cox regression model adjusted for age, EuroSCORE II, symptoms, left ventricular ejection fraction (LVEF), left ventricular end-systolic diameter (LV ESD) and DMR severity, the number of secondary outcome determinants was independently associated with post-operative all-cause mortality, with adjusted hazard ratios of 1.56 [95% confidence interval (CI): 1.11–2.20, P = 0.011], 1.78 (95% CI: 1.23–2.58, P = 0.002) and 2.58 (95% CI: 1.73–3.83, P < 0.0001) for patients with one, two, and three or four secondary outcome determinants, respectively. A model incorporating the number of secondary outcome determinants demonstrated a higher C-index and was significantly more concordant with post-operative mortality than models incorporating traditional Class I indications alone [the presence of symptoms (P = 0.0003), or LVEF ≤60% (P = 0.006), or LV ESD ≥40 mm (P = 0.014)], while there was no significant difference in concordance observed compared with a model that incorporated the number of Class I indications for surgery combined (P = 0.71). In this large cohort of patients treated surgically for DMR, the presence and number of secondary outcome determinants was independently associated with post-surgical survival and demonstrated better outcome discrimination than traditional Class I indications for surgery. Randomised controlled trials are needed to determine if patients with severe DMR who demonstrate a cardiac phenotype with an increasing number of secondary outcome determinants would benefit from earlier surgery. CI = confidence interval, DMR = degenerative mitral regurgitation, FTR = functional tricuspid regurgitation, HR = hazard ratio, LA = left atrium, LAVI = left atrial volume index, PA = pulmonary artery, sPAP = systolic pulmonary artery pressure, TR = tricuspid regurgitation, US = United States

Aims: Paravalvular regurgitation (PVR) after transcatheter aortic valve implantation (TAVI) is associated with increased morbidity and mortality. The effect of transcatheter interventions to treat PVR after the index TAVI was investigated.Methods and results: A registry of consecutive patients who underwent transcatheter intervention for ≥ moderate PVR after the index TAVI at 22 centers. The principal outcomes were residual aortic regurgitation (AR) and mortality at 1 year after PVR treatment. A total of 201 patients were identified: 87 (43%) underwent redo-TAVI, 79 (39%) plug closure, and 35 (18%) balloon valvuloplasty. Median TAVI-to-re-intervention time was 207 (35; 765) days. The failed valve was self-expanding in 129 (63.9%) patients. The most frequent devices utilized were a Sapien 3 valve for redo-TAVI (55, 64%), an AVP II as plug (33, 42%), and a True balloon for valvuloplasty (20, 56%). At 30 days, AR ≥ moderate persisted in 33 (17.4%) patients: 8 (9.9%) after redo-TAVI, 18 (25.9%) after plug, and 7 (21.9%) after valvuloplasty (P = 0.036). Overall mortality was 10 (5.0%) at 30 days and 29 (14.4%) at 1 year: 0, 8 (10.1%), and 2 (5.7%) at 30 days (P = 0.010) and 11 (12.6%), 14 (17.7%), and 4 (11.4%) at 1 year (P = 0.418), after redo-TAVI, plug, and valvuloplasty, respectively. Regardless of treatment strategy, patients in whom AR was reduced to ≤ mild had lower mortality at 1 year compared with those with AR persisting ≥ moderate [11 (8.0%) vs. 6 (21.4%); P = 0.007].Conclusion: This study describes the efficacy of transcatheter treatments for PVR after TAVI. Patients in whom PVR was successfully reduced had better prognosis. The selection of patients and the optimal PVR treatment modality require further investigation.