A hybrid clinical and electrocardiographic score to predict the origin of outflow tract ventricular arrhythmias

BACKGROUND

To predict the outflow tract ventricular arrhythmias (OTVA) site of origin (SOO) before the ablation procedure has important practical implications. The present study sought to prospectively evaluate the accuracy of a clinical and electrocardiographic hybrid algorithm (HA) for the prediction of OTVAs-SOO, and at the same time to develop and to prospectively validate a new score with improved discriminatory capacity.

METHODS

In this multicenter study, we prospectively enrolled consecutive patients referred for OTVA ablation (N = 202), and we divided them in a derivation sample and a validation cohort. Surface ECGs during OTVA were analyzed to compare previous published ECG-only criteria and to develop a new score.

RESULTS

In the derivation sample (N = 105), the correct prediction rate of HA and ECG-only criteria ranged from 74 to 89%. R-wave amplitude in V3 was the best ECG parameter for discriminating LVOT origin in V3 precordial transition (V3PT) patients, and was incorporated to the novel weighted hybrid score (WHS). WHS correctly classified 99 (94.2%) patients, presenting 90% sensitivity and 96% specificity (AUC 0.97) in the entire population; WHS mantained a 87% sensitivity and 91% specificity (AUC 0.95) in patients with V3PT subgroup. The high discriminatory capacity was confirmed in the validation sample (N = 97): the WHS exhibited an AUC (0.93), and a WHS ≥ 2 allowed a correct prediction of LVOT origin in 87 (90.0%) cases, yielding a sensitivity of 87% and specificity of 90%; moreover, the V3PT subgroup showed an AUC of 0.92, and a punctuation ≥ 2 predicted an LVOT origin with a sensitivity of 94% and specificity of 78%.

CONCLUSIONS

The novel hybrid score has proved to accurately anticipate the OTVA's origin, even in those with a V3 precordial transition. A Weighted hybrid score. B Typical examples of the use of the weighted hybrid score. C ROC analysis of WHS and previous ECG criteria for prediction of LVOT origin in the derivation cohort. D ROC analysis of WHS and previous ECG criteria for prediction of LVOT origin in the V3 precordial transition OTVA subgroup.

Validation of a clinical model for predicting left versus right ventricular outflow tract origin of idiopathic ventricular arrhythmias

BACKGROUND

Prediction of the chamber of origin in patients with outflow tract ventricular arrhythmias (OTVA) remains challenging. A clinical risk score based on age, sex and presence of hypertension was associated with a left ventricular outflow tract (LVOT) origin. We aimed to validate this clinical score to predict an LVOT origin in patients with OTVA.

METHODS

In a two-center observational cohort study, unselected patients undergoing catheter ablation (CA) for OTVA were enrolled. All procedures were performed using an electroanatomical mapping system. Successful ablation was defined as a ≥80% reduction of the initial overall PVC burden after 3 months of follow-up. Patients with unsuccessful ablation were excluded from this analysis.

RESULTS

We included 187 consecutive patients with successful CA of idiopathic OTVA. Mean age was 52 ± 15 years, 102 patients (55%) were female, and 74 (40%) suffered from hypertension. A LVOT origin was found in 64 patients (34%). A score incorporating age, sex and presence of hypertension reached 73% sensitivity and 67% specificity for a low (0-1) and high (2-3) score, to predict an LVOT origin. The combination of one ECG algorithm (V2 S/V3 R-index) with the clinical score resulted in a sensitivity and specificity of 81% and 70% for PVCs with R/S transition at V3 .

CONCLUSION

The published clinical score yielded a lower sensitivity and specificity in our cohort. However, for PVCs with R/S transition at V3, the combination with an existing ECG algorithm can improve the predictability of LVOT origin.

A case of mistaken arrhythmogenic identity during pregnancy

Atypical LVOT ectopy can present with an RVOT morphology on ECG and differentiation to reveal this focus is in favor of benign idiopathic ventricular ectopy over an arrhythmogenic cardiomyopathy.

MANual vs. automatIC local activation time annotation for guiding Premature Ventricular Complex ablation procedures (MANIaC-PVC study)

AIMS

To assess potential benefits of a local activation time (LAT) automatic acquisition protocol using wavefront annotation plus an ECG pattern matching algorithm [automatic (AUT)-arm] during premature ventricular complex (PVC) ablation procedures.

METHODS AND RESULTS

Prospective, randomized, controlled, and international multicentre study (NCT03340922). One hundred consecutive patients with indication for PVC ablation were enrolled and randomized to AUT (n = 50) or manual (MAN, n = 50) annotation protocols using the CARTO3 navigation system. The primary endpoint was mapping success. Clinical success was defined as a PVC-burden reduction of ≥80% in the 24-h Holter within 6 months after the procedure. Mean age was 56 ± 14 years, 54% men. The mean baseline PVC burden was 25 ± 13%, and mean left ventricular ejection fraction (LVEF) 55 ± 11%. Baseline characteristics were similar between the groups. The most frequent PVC-site of origin were right ventricular outflow tract (41%), LV (25%), and left ventricular outflow tract (17%), without differences between groups. Radiofrequency (RF) time and number of RF applications were similar for both groups. Mapping and procedure times were significantly shorter in the AUT-arm (25.5 ± 14.3 vs. 32.8 ± 12.6 min, P = 0.009; and 54.8 ± 24.8 vs. 67.4 ± 25.2, P = 0.014, respectively), while more mapping points were acquired [136 (94-222) AUT vs. 79 (52-111) MAN; P < 0.001]. Mapping and clinical success were similar in both groups. There were no procedure-related complications.

CONCLUSION

The use of a complete automatic protocol for LAT annotation during PVC ablation procedures allows to achieve similar clinical endpoints with higher procedural efficiency when compared with conventional, manual annotation carried out by expert operators.

The ratio of main pulmonary artery to ascending aorta diameter is associated with the right ventricular outflow tract ventriculararrhythmias

BACKGROUND

Although outflow tract (OT) ventricular arrhythmias (VAs) are generally regarded as benign, the relationship between circulation pressure and VAs has received considerable attention in recent years. Previous studies have shown that the ratio of main pulmonary artery (MPA) to ascending aorta (AA) diameter is associated with pulmonary pressure. Here, we investigated whether an elevated MPA/AA ratio is associated with right ventricular OT (RVOT) VAs.

METHODS

A total of 67 patients with OT VAs (47 patients with RVOT and 20 patients with LVOT) who underwent cardiac multidetector computed tomography and radiofrequency ablation were enrolled in this study. MPA and AA diameters were measured at the level of the bifurcation of the pulmonary artery. According to the MPA/AA ratio, patients were further divided into two groups: the MPA/AA ratio abnormal group (n = 19), which is defined as MPA/AA ratio ≥ 0.9, and the MPA/AA ratio normal group (n = 48) consisting of patients with an MPA/AA ratio < 0.9.

RESULTS

Patients with RVOT VAs exhibited an elevated MPA/AA ratio (0.84 ± 0.11 vs. 0.75 ± 0.11, p = 0.006). Furthermore, this MPA/AA ratio was shown to be an independent predictor for RVOT VAs (p = 0.013, 95% confidence interval: 1.016-1.145), with an abnormal MPA/AA ratio increasing the odds of RVOT VAs 5.1-fold in patients with OT VAs.

CONCLUSION

Patients with RVOT VAs exhibited significantly higher MPA/AA ratios compared with those LVOT VAs. The MPA/AA ratio was showed to be an independent predictor RVOT VAs.

Premature ventricular complex site of origin and ablation outcomes in patients with prior myocardial infarction

BACKGROUND

Frequent premature ventricular complexes (PVCs) are common after a myocardial infarction (MI), but data on PVC ablation in this population are limited.

OBJECTIVE

The purpose of this study was to analyze data on PVC ablation in post-MI patients.

METHODS

Three hundred thirty-two patients with frequent PVCs and left ventricular (LV) dysfunction were prospectively studied. Data from 67 patients (20%; age 63 ± 10 years; 65 men [93%]) with previous MI were compared with the remaining 265 patients.

RESULTS

PVCs in post-MI patients originate predominantly from the LV (92% LV vs 6% right ventricle [RV]; P <.001). The most frequent sites of origin (SOO) were MI scar in 23 patients (34%) and left ventricular outflow tract (LVOT) in 22 patients (33%). A papillary muscle origin was more frequent in post-MI patients (16% vs 4%; P = .001), whereas an RV outflow tract origin was less frequent (1% vs 33%; P <.001) compared to patients without MI. In post-MI patients, PVC burden decreased from 29% ± 12% at baseline to 4.6% ± 7% (P <.001); left ventricular ejection fraction (LVEF) improved from 33.6% ± 8% to 42% ± 10% (P <.001); and New York Heart Association functional class improved from 2.1 ± 0.7 to 1.4 ± 0.5 points (P <.001) at 12 months. Compared with the remaining 265 patients, there were no differences in acute ablation success (85% vs 85%; P = .45), complication rate (6% vs 6%; P = .41), or absolute improvement in LVEF (8.8 ± 10 vs 9.9 ± 11 absolute points; P = .38).

CONCLUSION

PVC ablation significantly improves cardiac function and functional status in post-MI patients. PVCs predominantly originate from MI scar and LVOT. A papillary muscle SOO was found to be strongly associated with previous MI.

Mapping and Ablation of Ventricular Outflow Tract Arrhythmias

Arrhythmias arising from the ventricular outflow tracts are commonly encountered. Although largely benign, they can also present with heart failure and sudden cardiac death. Mapping and ablation of these arrhythmias is commonly performed in the electrophysiology laboratory with a high success rate, but occasionally can prove challenging to abolish. This article discusses the mapping and ablation of outflow tract arrhythmias and the challenges that can be overcome by a systematic approach.

Asymptomatic ventricular premature depolarizations are not necessarily benign

AIMS

Most patients with idiopathic ventricular premature depolarizations (VPDs) complain of symptoms related to this arrhythmia, but some patients are asymptomatic even with a high VPD burden. Our understanding of the relationship between symptoms and cardiomyopathy related to this arrhythmia remains limited.

METHODS AND RESULTS

We evaluated 801 subjects (381 men; mean age, 55 ± 17 years) who visited our outpatient clinic. All subjects were diagnosed with frequent VPDs (1% or >1000 beats/day). The patients were divided into two groups according to the presence or absence of typical VPD symptoms (palpitations or skipped beats during VPDs): symptomatic patients (n = 455) and asymptomatic patients (n = 346). Clinical and electrocardiogram parameters were compared between these two groups. In the symptomatic group, palpitations were the most frequent symptom (91%). Daily VPD burden (P = 0.90) and electrocardiogram parameters (P>0.05) did not differ significantly between groups. The incidence of frequent VPDs with left ventricular dysfunction was significantly higher in the asymptomatic group (symptomatic patients, 3.0%; asymptomatic patients, 10.5%; P < 0.001).

CONCLUSION

The absence of typical VPD-related symptoms may be a risk factor for cardiomyopathy and be associated with an adverse outcome.