Suppression Of Premature Ventricular Contractions Research Articles

Imaging-derived tissue visualization guides catheter ablation of premature ventricular contractions

Abstract Background The presence of myocardial scarring is associated with worse outcomes after catheter ablation of premature ventricular contractions (PVCs). Three-dimensional substrate characterization is emerging for peri-procedural ablation guidance, but its value for tissue visualization during PVC ablation is unknown. Purpose The aim of the present study was to assess the impact of imaging-derived tissue visualization on lesion planning, procedural and clinical outcomes of PVC ablation. Methods Thirteen consecutive patients (92.3% male, 62.2±12.4 years) undergoing unipolar (n=8) or bipolar (n=5) PVC catheter ablation with integrated three-dimensional imaging from multidetector computed tomography or cardiac magnetic resonance imaging were included. All patients presented with assumed myocardial scarring due to an underlying cardiomyopathy and/or after previous ablation. Results Among all patients (30.8% (peri-)myocarditis, 20.0% ischemic, 15.4% dilated cardiomyopathy, 15.4% idiopathic, 7.7% nonischemic, 7.7% congenital heart disease) undergoing ablation of 20 PVC morphologies (median 1 (IQR 1-2) per patient; 75.0% non-outflow tract; 70.0% left-sided), myocardial scarring was present in 11/13 (84.6%). Wall thinning <5 mm covering an area of 36.1±17.8 cm² contained the PVC origin in 4/13 (30.8%) patients and was safely targeted with radiofrequency lesions with up to 45 W (maximum power: median 32 W (IQR 30-35)) (Figure 1). Imaging-guided bipolar ablation was performed in 5/8 (62.5%) patients with previously therapy-refractory PVCs including foci at the left ventricular summit and the right ventricular outflow tract each in 2 and the left coronary cusp in one patient (Figure 2). PVCs were efficiently suppressed with less radiofrequency lesions (5.4±3.8 vs. 55.8±36.9; p=0.0160) with shorter duration (4.1±3.2 min vs. 23.3±13.5 min; p=0.0152) compared to prior unipolar ablation. Bipolar lesions resulted in a higher impedance (158 Ω (IQR 101-174) vs. 106 Ω (IQR 99-124); p=0.0025), while requiring a lower temperature (36 °C (IQR 35-38) vs. 39 °C (IQR 36-43); p=0.0001) and less power (26 W (IQR 20-30) vs. 30 W (IQR 25-31); p=0.0376). Complete suppression of the clinical PVC was reached in all 13 patients. During a follow-up of 396.8±299.7 days, PVC burden decreased from 20.1±14.3% to 1.7±1.6% (p=0.0172). Conclusions Imaging-derived tissue visualization enables determination of myocardial wall thinning <5 mm as a substrate for recurrent PVCs, which can be safely targeted. Three-dimensional imaging efficiently guides high power lesion application and bipolar ablation of PVCs at anatomically challenging foci.Anatomically challenging fociImaging-guided bipolar ablation

Unipolar and bipolar electrograms to predict successful ablation site of premature ventricular contractions originating from the free wall of the tricuspid annulus.

This study aimed to identify the characteristics of unipolar and bipolar electrogram (UniEGM and BiEGM) in guiding successful ablation of premature ventricular contractions (PVCs) originating from the free wall of the ventricular aspect of the tricuspid annulus (TA). We hypothesized that the negative concordance pattern (NCP) on the onset of UniEGM and BiEGM, together with the least value of the difference between the earliest BiEGM and UniEGM dV/dTmax, might improve the accuracy of conventional mapping. Thirty consecutive patients who underwent successful catheter ablation from February 2018 to July 2021 were retrospectively analyzed. The BiEGM and UniEGM for successful ablation sites were compared with those for non-successful ablation sites. Among the 30 patients, 30 successful and 26 nonsuccessful ablation sites were compared. The earliest activation time of the BiEGM (BiEGMoneset-QRS) was 25 ± 6 ms for the successful ablation sites and 21 ± 6 ms for the nonsuccessful ablation sites (p = .47). The value of the difference in the earliest BiEGM and UniEGM dV/dTmax differed between successful and nonsuccessful ablation sites (6.4 ± 3.6 ms vs. 10.4 ± 6.8 ms). NCP was observed at 90.0% and 42.3% of the successful and nonsuccessful ablation sites, respectively. Alignment of NCP and BiEGMonset-UniEGM ≤6 ms was applied as the mapping criterion for successful PVC suppression (73.1% sensitivity and 87.7% specificity). The area under the receiver-operating characteristic curve for this cutoff was 0.85. Mapping based on an NCP at the onset of the BiEGM and UniEGM and the least difference value of the earliest BiEGM and UniEGM dV/dTmax had an excellent predictive value for successful ablation. These strategies may reduce the number of radiofrequency catheter ablation (RFCA) applications for free-wall tricuspid annular PVCs.

Use of Ripple mapping to enhance localization and ablation of outflow tract premature ventricular contractions.

Accurate localization of septal outflow tract premature ventricular contractions (PVCs) is often difficult due to frequent mid-myocardial or protected origin. Compared with traditional activation mapping, CARTO Ripple mapping provides visualization of all captured electrogram data without assignment of a specific local activation time and thus may enhance PVC localization. Electroanatomic maps for consecutive catheter ablation procedures for septal outflow tract PVCs (July 2018-December 2020) were analyzed. For each PVC, we identified the earliest local activation point (EA), defined by the point of maximal -dV/dt in a simultaneously recorded unipolar electrogram, and the earliest Ripple signal (ERS), defined as the earliest point at which three grouped simultaneous Ripple bars appeared in late diastole. Immediate success was defined as full suppression of the clinical PVC. Fifty-seven unique PVCs in 55 procedures were included. When ERS and EA were in the same chamber (RV, LV, or CS), the odds ratio for the successful procedure was 13.1 (95% confidence interval [CI] 2.2-79.9, p = .005). Discordance between sites was associated with a higher likelihood of needing multi-site ablation (odds ratio [OR] 7.9 [1.4-4.6; p = .020]). Median EA-ERS distance in successful versus unsuccessful cases was 4.6 mm (interquartile range 2.9-8.5) versus 12.5 mm (7.8-18.5); (p = .020). Greater EA-ERS concordance was associated with higher odds of single-site PVC suppression and successful septal outflow tract PVC ablation. Visualization of complex signals via automated Ripple mapping may offer rapid localization information complementary to local activation mapping for PVCs of mid-myocardial origin.

Similarly high success and low complication rates of catheter ablation for idiopathic premature ventricular contractions from the left and right ventricular outflow tract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Catheter ablation is the first line treatment for idiopathic premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT) but not from the left ventricular outflow tract (LVOT), due to presumed lower success and higher complication rates in the LVOT. In this observational single center study we analyzed success rates and complication rates in patients undergoing catheter ablation for idiopathic PVCs with an inferior axis. Methods Patients undergoing catheter ablation for idiopathic PVCs with an inferior axis at Hannover Heart Rhythm Center between 2012 and 2020 were included. Patients were excluded if no activation mapping could be performed because of low PVC activity. Ablation success was defined as complete suppression of the index PVC at the end of the procedure. Results 108 patients (53% male, age 53 ± 17 years) with predominantly symptomatic (94%) PVCs with one (72%), two (20%) or more (8%) morphologies and a PVC count of 22063 ± 14426 /24h were included. 47 PVCs (44%) were located in the RVOT (21 anterior RVOT and 26 septal RVOT) and 39 PVCs (36%) in the LVOT (11 lateral LVOT, 5 septal LVOT, 8 RCC, 2 ACC, 13 LCC). 14 PVCs (13%) had the origin close to the CS/LV summit and 8 PVCs (7%) in the parahisian region. Overall success rate was 82%. Success rates for RVOT and LVOT origin were 98% (46/47 cases) and 97% (38/39 cases) respectively. No significant differences in procedure time (145 ± 68 vs. 158 ± 72 min), ablation time (441 ± 328 vs. 462 ± 307 sec), fluoroscopy time (496 ± 521 vs. 519 ± 473 sec) or minor complications (5 vs. 8) were observed for outflow tract PVCs, and no major complications occurred in this group. However, 3 major complications and significantly lower success rates were observed for non-outflow tract PVCs (0/8 for parahisian origin, 4/14 (29%) for CS/LV summit origin). 2 patients with a parahisian focus experienced higher degree AV block and 1 patient with an LV summit focus had a pericardial tamponade. Conclusion Catheter ablation of PVCs with LVOT origin can be performed with similarly high success and low complication rates compared to PVCs with RVOT origin, and therefore could be considered as first-line therapy like RVOT PVCs. On the other hand, identification of PVCs with a parahisian or CS/LV summit focus should be aspired before an ablation procedure, as these localizations are associated with poorer ablation outcome and higher complication rates.

Prediction of ablation success of idiopathic premature ventricular contractions with an inferior axis using the twelve-lead electrocardiogram

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Catheter ablation is the first line treatment for idiopathic premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT) but not left ventricular outflow tract (LVOT). However, differentiating the two using the twelve-lead electrocardiogram (ECG) is challenging. As an alternative strategy to guide clinical decision-making, we sought to find ECG criteria that predict outcome of catheter ablation directly rather than focus only. Methods This observational single center study included patients undergoing an ablation procedure for idiopathic PVCs with an inferior axis (positive QRS in leads II, III and aVF) at Hannover Heart Rhythm Center between 2012 and 2020. Patients were excluded if no activation mapping was performed because of low PVC activity. A complete suppression of the index PVC at the end of the ablation procedure was considered as ablation success. PVC axis was estimated with the help of the hexaxial reference system, and as an objective control was also calculated measuring QRS voltages and using three formulas: Arctan (aVF/I), Arctan ((2*II-I)/(Sqr(3)*I)) and +/-Arctan ((2*aVF)/(Sqr(3)*I)). Results The analysis included 108 patients (53% male, age 53 ± 17 years) with a PVC count of 22063 ± 14426 /24h. The dominant PVC had Left Bundle Branch Block (LBBB) like morphology in 80%, a mean transition (TZ)-score of 2.3 ± 1.2 and a mean axis of 87 ± 15°, estimated with the help of the hexaxial system. There was no significant difference between axis as estimated with the help of the hexaxial system compared to calculation via any of the formulas (87 ± 14, 87 ± 12 and 86 ± 16°, respectively). Overall ablation success was 82%. Considering ablation outcome according to the identified PVC localization, 46 of 47 cases (97.9%) of RVOT focus and 38 of 39 cases (97.4%) of LVOT focus were successful. On the other hand, all 8 cases with a parahisian focus were not successful and only 4 of 14 cases (28.6%) with a CS/LV summit focus were successful. Two ECG criteria were found to predict ablation failure: a more leftward PVC axis (p=0.015), which was associated with a parahisian focus (p<0.001), and an early precordial transition compared to the QRS complex during AV-nodal conduction (p=0.016), which was associated with a CS/LV summit focus (p<0.001). Using ROC statistics, a cutoff value of 75° for PVC axis and of 2.75 for TZ-Score index predicted ablation success with a positive predictive value of 93% if neither parameter applied (prediction of ablation failure, if either applied, 53 %). Conclusion Two ECG criteria – a more leftward PVC axis and an early precordial transition compared to sinus rhythm – predicted ablation failure and a parahisian or CS/LV summit focus. These parameters should be considered when evaluating a patient for catheter ablation of PVCs with an inferior axis.

P166 LEFT VENTRICULAR SUMMIT PVC–INDUCED CARDIOMYOPATHY: A CASE REPORT

Abstract A 76 y.o. patient referred to our attention for syncopal and presyncopal episodes. His ECG showed several premature ventricular contractions (PVC) with the morphology of a right bundle branch block (RBBB)– positive concordance in precordial leads and transtion in V3 lead– and an inferior axis. Echocardiographic finding was a moderate reduced ejection fraction. Furthermore coronarography did not identify critical stenosis, excluding an ischemic etiology. Cardiac MRI was performed, confirming the reduce ejection fraction and excluding LGE. Because of high burden of 25000 PVCs on 24 h ECG registration and progressive deterioration of ejection fraction, despite antiarrhythmic drugs, catheter ablation was considered. An high density multielectrode mapping catheter was used and an initial right ventricular mapping was perfomed, recording local electrograms but without identification of a clear earliest site of activation. Therefore a retrograde transaortic left ventricular mapping was performed. Earliest site of activation was not significant (about 15 milliseconds), as well as percentage of correlation during pace–mapping. Epicardial mapping through coronary sinus into the anterior interventricular vein (AIV) showed a significant earliest activation site (greater than 30 ms) and a negative unipolar signal (QS) was detected. Pacing in this region highlighted a significant percentage of correlation with native PVC (92%), then catheter ablation was attempted. A first short duration application of radiofrequency was erogated on the endocardial side in front of the projection of the catheter in the AIV, because of possible risks of procedure, obtaining a temporary PVC suppression. Subsequently, after execution of a coronary angiogram proving a distance of the ablator in AIV and IVA/Cx vessels greater than > 1 cm, an endovenous approach was attempted with application of radiofrequency into the AIV, obtaing complete PVC suppression. At a 6 months follow–up ejection fraction improved (FE 50%) and PVC were not detected. Discussion Epicardial approach throught coronary sinus is an effective strategy to map and ablate arrhythmias of left ventricular summit. In addiction this stretegy allows a less invasive epicardial approach than other procedures, requiring a cardiosurgery standby.

Clinical observation of radiofrequency ablation for premature ventricular contractions originating from uncommon His-Purkinje sites

BackgroundRadiofrequency catheter ablation (RFCA) of premature ventricular contractions (PVCs) originating from common locations such as the proximal and middle fascicles of the His-Purkinje system (HPS) has been established as an effective therapy. This report aims to highlight the electrophysiological properties and RFCA of PVCs originating from uncommon locations of the HPS.MethodsAmong 57 patients with fascicular PVCs, 3 with fascicular PVCs originating from uncommon sites were retrospectively analyzed.ResultsWe identified three patients with PVCs originating separately from diseased fascicles, the dead-end tract (DET), and the distal fascicle. In contrast to PVCs originating from the proximal and medial fascicles, the fascicular potentials could not be recorded at the target sites of patients with PVCs originating from diseased fascicles or the distal fascicle during sinus rhythm. However, these PVCs were successfully ablated from the HPS, guided by recording their earliest fascicular potentials in PVCs. PVCs originating from the DET are morphologically consistent with those originating from the proximal left anterior fascicle or the distal left bundle branch. The corresponding tiny sharp potential of the DET could be mapped, and RFCA of the right coronary cusp achieved successful suppression of PVCs.ConclusionsThe knowledge of the different electrophysiological characteristics of fascicular PVCs originating from uncommon locations can contribute to precise mapping and ablation. For such arrhythmia, the target site for successful ablation should be identified by earliest fascicular potential.

Limitations of Unipolar Signals in Guiding Successful Outflow Tract Premature Ventricular Contraction Ablation.

Unipolar electrograms (UniEGMs) are commonly used to annotate earliest local activation of focal arrhythmias. However, their utility in guiding premature ventricular contractions (PVCs) ablation may be limited when the PVC source is less superficial. The authors sought to compare bipolar electrograms (BiEGMs) vs UniEGMs in guiding successful ablation of right ventricular outflow tract (RVOT) vs intramural outflow tract (OT) PVCs. The authors hypothesized that: 1) earliest bipolar local activation time (LATBi) would better guide mapping and ablation, vs UniEGM dV/dt (LATUni) or QS morphology; and 2) LAT differences using bipolar vs unipolar EGMs (ΔLATBi-Uni) would be greater for intramural OT than RVOT PVCs. Consecutive patients undergoing successful PVC ablation 2017 to2020 requiring only RVOT or RVOT+left ventricular OT (RVOT+LVOT) ablation were retrospectively analyzed. BiEGMs and UniEGMs at successful ablation sites were compared. Of 70 patients, 50 required RVOT-only, and 20 required RVOT+LVOT ablation for acute and long-term PVC suppression. Mean ΔLATBi-Uni was lower for RVOT vs RVOT+LVOT groups (9.3 ± 6.4ms vs 17.4 ± 9.9ms; P< 0.01). QS UniEGM was seen in 78% of RVOT, compared with 53% of RVOT+LVOT patients (P< 0.016). RVOT+LVOT sites most frequently included the posteroseptal RVOT and adjacent LVOT (73%), and 43% lacked a QS unipolar EGM. ΔLATBi-Uni≥15ms best distinguished sites in which RVOT-only vs RVOT+LVOT ablation achieved acute PVC suppression (area under the curve: 0.77). Earliest BiEGM activation guides successful ablation of OT PVCs better than UniEGM-guided analysis, especially when an intramural PVC source is present.

B-PO03-204 DON’T THROW THE BABY OUT WITH THE BATHWATER - VOLTAGE MAPPING STILL MATTERS

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart condition characterized with fibrofatty replacement of myocardium with an increased risk of arrhythmia and sudden cardiac death. Multimodality imaging including cardiac magnetic resonance (CMR) can help deep phenotype cases. Clinical case where voltage mapping identified fibrofatty myocardium undetected by CMR. N/A A 46-year-old female presented with palpitations, ventricular tachycardia (VT) and premature ventricular contractions (PVCs) burden of 17%. The intrinsic sinus ECG was normal She preferred ablation and pre-procedure CMR showed dilated right ventricle without evidence of dyskinesia, inflammation, late gadolinium enhancement, or fatty infiltration. The patient underwent an EP study arriving in sinus rhythm and had dominant clinical PVC with a left bundle inferiorly directed axis, V5 transition and negative in lead I and aVL placing it at the anterior-septal right ventricular outflow tract. Having good pace maps there burst pacing with the ablation catheter induced clinical VT similar to the PVC; radiofrequency ablation slowed and terminated it under 10 seconds. After suppression of VT and PVCs, a detailed voltage map of the RV was obtained demonstrating significant bipolar and unipolar voltage abnormalities on the RV free wall where ablation had not been performed. This scar pattern was suggestive of ARVC Subsequent genetic testing confirmed pathogenic PKP2 mutation. Voltage mapping remains a useful adjunct tool for deep phenotyping and can detect diseased myocardium which may not be visualized with other imaging modalities.

Does Premature Ventricular Contractions Affect Exercise Capacity in Teenagers with Normal Hearts?

Premature ventricular contractions (PVCs) are common in teenagers even in the absence of structural heart disease or channelopathy. The suppression of PVCs with exercise is a favorable prognostic indicator. There is a paucity of data regarding the relationship between exercise capacity and PVC burden in this population.Our objective was to evaluate the association between various exercise stress parameters and PVC burden ascertained with a 24h Holter in children without structural heart disease and/or channelopathy. In this retrospective study, 447 patient's charts with a diagnosis of PVC were reviewed at a single tertiary center. The study cohort consisted of ninety one patients with no structural heart disease or channelopathy who underwent an echocardiogram, maximal stress test, and 24h Holter monitor. The cohort was divided into two groups based on PVC burden by 24-h Holter monitoring: < 10% and ≥ 10%. Peak oxygen uptake (VO2 in ml/kg/min), an indicator of maximal aerobic capacity, was collected. Other exercise parameters included a) percentage of predicted VO2 (%VO2) based on age, weight, height, and gender b) percent oxygen pulse, c) Anaerobic threshold (AT), and d) Metabolic equivalents. Demographic and exercise stress test-derived parameters were compared between the two groups using student t test and a p value < 0.05 was considered significant. In our cohort of 91 patients, the mean (SD) age at exercise was 14.5 (3.2) years with 56 (62%) males. Left ventricle shortening fraction (LVFS) was ≥ 28% in all enrolled patients. PVCs were monomorphic in 72(80%) patients. The mean (SD) PVC burden was 14.43% (12.3) ranging from 0.1 to 49.8%. PVC burden was ≥ 10% in 48 (53%) patients. Eighty eight (97%) patients in the study cohort had suppression of PVCs with exercise. There were no significant differences between the two groups (< 10% vs. ≥ 10% PVC burden) with respect to demographic or exercise test-derived parameters. Univariate regression between PVC burden and %VO2 did not show significant correlation (r = - 0.04, p = 0.75). Children even with ≥ 10% PVC burden did not demonstrate any objective decrease in their exercise capacity. A plausible reason for no difference in exercise capacity in our cohort may be due to lower PVC load or shorter duration of PVCs compared to adults.

Outcomes of Premature Ventricular Contraction-Cardiomyopathy in the Veteran Population: ASecondary Analysis of the CHF-STAT Study.

This study sought to assess the rate and outcomes of premature ventricular contractions (PVC)-cardiomyopathy from the CHF-STAT (Survival Trial of Antiarrhythmic Therapy in Congestive Heart Failure) trial, a population with cardiomyopathy (left ventricular [LV] ejection fraction of<40%) and frequent PVCs (>10 PVCs per hour). PVCs are associated with heart failure and PVC-cardiomyopathy. The prevalence of PVC-cardiomyopathy and outcome benefits of PVC suppression are not clear. A secondary analysis of the CHF-STAT study was performed to compare the rate of successful PVC suppression (≥80% PVC reduction), LV recovery (defined as improvement in LV ejection fraction of≥10% points), and PVC-cardiomyopathy between amiodarone and placebo groups at 6months. PVC-cardiomyopathy was defined if both PVC reduction of≥80% and LV ejection fraction improvement of≥10% were present at 6months. Cardiac events (death or resuscitated cardiac arrest) were compared between PVC-cardiomyopathy versus non-PVC-cardiomyopathy during a 5-year follow-up. The rates of successful PVC suppression and LV recovery were significantly higher in the amiodarone (72% and 39%, respectively) when compared to the placebo group (12% and 16%, respectively; p<0.001), regardless of cardiomyopathy etiology. PVC-cardiomyopathy was present in 29% and 1.8% of patients in the amiodarone and placebo groups, respectively (p<0.001). Similar PVC-cardiomyopathy rates were found in ischemic (24% amiodarone vs. 2% placebo; p<0.001) and nonischemic populations (41% amiodarone vs. 1.5% placebo; p<0.001). Death and resuscitated cardiac arrest were significantly lower in patients with PVC-cardiomyopathy and those treated with amiodarone. The overall prevalence of PVC-cardiomyopathy in the CHF-STAT study was significant regardless of ischemic substrate (29%, overall population; 41%, nonischemic cardiomyopathy). Treatment of PVC-cardiomyopathy with amiodarone is likely to improve survival in this high-risk population.

Speckle Tracking Echocardiography in Pediatric Patients with Premature Ventricular Contractions.

Premature ventricular contractions (PVCs) in pediatric patients without structural heart disease and normal left ventricular systolic function rarely require therapy, though it is unknown whether these patients have subclinical cardiac dysfunction. Speckle tracking echocardiography is an additional means of evaluating cardiac function in asymptomatic pediatric PVC patients with normal standard measures of left ventricular (LV) function. Asymptomatic pediatric patients (< 21years) without congenital heart disease, LV ejection fraction (LVEF) ≥ 55% and PVC burden ≥ 5% on 24-h Holter monitor were included. Demographic information, exercise stress test results, standard echocardiographic measures of LV systolic function and PVC morphology by 12-lead ECG were collected. Peak global systolic longitudinal strain (GLS) from apical four-chamber view was analyzed offline. 29 patients were identified (mean age 11.7 ± 5.8years, 49.2 ± 25.3kg, 59% male). Mean PVC burden was 12.0 ± 7.0% (range 5-37.5%). 14/29 (48%) had exercise stress testing with evidence of PVCs; 9/14 (64%) had PVC suppression at a mean heart rate (HR) of 160 ± 23bpm and 5/14 (36%) did not suppress at a mean maximum HR of 188 ± 9bpm. All patients had normal strain values by speckle tracking echocardiography (mean LV GLS - 22.5 ± 2.0%, LV global circumferential strain - 25.3 ± 3.9 and RV GLS - 24.1 ± 3.0%). There was no correlation between PVC burden and cardiac function parameters. Asymptomatic pediatric patients without structural heart disease, preserved LVEF/shortening fraction and PVC burden ≥ 5% demonstrated normal cardiac function including strain patterns indicating no evidence of subclinical cardiac dysfunction. Larger scale studies and longitudinal evaluation of left ventricular function using speckle tracking echocardiography is warranted in this population.

Frequent Premature Ventricular Contractions and Cardiomyopathy, Chicken and Egg situation.

Premature ventricular contractions (PVCs) are usually regarded as benign in the absence of structural heart disease. However, frequent PVCs can lead to depressed LV function, called PVC-induced cardiomyopathy and can be reversible after suppression of PVCs. On the other hand, PVCs can be a part of underlying structural heart disease and may be linked to increased risk of sudden death. In this work, we reviewed the current literature on PVC-induced cardiomyopathy based on a case presentation.

Negative concordance pattern in bipolar and unipolar recordings: An additional mapping criterion to localize the site of origin of focal ventricular arrhythmias

The relevance of the temporal relationship between a unipolar electrogram (UEGM) and a bipolar electrogram (BEGM) in determining the site of origin (SOO) of focal arrhythmias has been largely demonstrated. We sought to demonstrate that a negative concordance in the initial forces of these EGMs is also helpful in predicting the SOO of premature ventricular contractions (PVCs). Mapping and radiofrequency (RF) ablation were performed in 41 patients with symptomatic PVCs in the absence of structural heart disease. Simultaneous recordings of the minimally filtered (0.5-500 Hz) UEGM and filtered BEGM (30-500 Hz) were analyzed at 247 mapping sites, where RF was attempted. EGMs of 63 mechanically induced PVCs were separately analyzed as a validation group. All ablation sites had a QS pattern in the UEGM. Acute PVC suppression was defined as a complete disappearance of ventricular ectopic beats after a 60-second pulse of RF. RF ablation obtained PVC suppression (RF+) in 33 of 247 sites (13.3%). A negative concordance pattern (NCP) during the initial 20 ms of both UEGM and BEGM was observed in 31 of 33 (94%) RF+ sites compared with 10 of 214 (4%)RF- sites (P < .0001). The NCP criterion demonstrated to be an additional powerful predictor of acute RF success with sensitivity, specificity, positive predictive value, and negative predictive value of 94%, 95%, 76%, and 99%, respectively. Similarly to RF+ sites, the NCP was observed in 60 of 63 sites (95.2%) in the mechanical PVC group. An NCP in both UEGM and BEGM may be an additional criterion that helps to localize the SOO of focal ventricular arrhythmias.

Frequent Premature Ventricular Contractions: An Electrical Link to Cardiomyopathy.

Heart failure is common and is associated with significant morbidity and mortality. Identifying potentially modifiable risk factors for the development of ventricular dysfunction is important in both the prevention and the treatment of this condition. Arrhythmia disorders are increasingly recognized as contributory to the development of ventricular failure. Poorly controlled supraventricular tachyarrhythmias, altered left ventricular activation due to left bundle branch block or right ventricular pacing, and frequent premature ventricular contractions (PVCs) constitute the main subtypes of arrhythmia disorders that are associated with the development of ventricular dysfunction. PVCs are common and are considered benign in the absence of structural heart disease. Frequent PVCs, defined as greater than 20% of all QRS complexes on standard 24-hour Holter monitoring, are associated with the presence or subsequent development of left ventricular dilatation and dysfunction. Catheter ablation of frequent PVCs has been demonstrated to be effective at PVC suppression and is associated with improvement or normalization of ventricular function; thus defining a specific, reversible form of ventricular dysfunction termed PVC cardiomyopathy. In patients presenting with high burden PVCs, an assessment for symptoms and associated cardiomyopathy is warranted and, in the appropriate clinical setting, PVC catheter ablation may be a reasonable treatment option.

Predicting utility of exercise tests based on history/holter in patients with premature ventricular contractions.

Premature ventricular contractions (PVCs) are considered benign in patients with structurally normal hearts, particularly if they suppress with exercise. Catecholaminergic polymorphic ventricular tachycardia (CPVT) requires exercise testing to unmask the malignant phenotype. We studied risk factors and Holter monitor variables to help predict the necessity of exercise testing in patients with PVCs. We retrospectively reviewed 81 patients with PVCs that suppressed at peak exercise and structurally normal hearts referred to the exercise laboratory in 2011. We reviewed 11 patients from 2003 to 2012 whose PVCs were augmented at peak exercise (mean age 13±4years; 52% male, 180 exercise studies). We recorded clinical risk factors and comorbidities (family history of arrhythmia or sudden unexpected death [SUD], presence of syncope) and Holter testing parameters. Family history of VT or SUD (P=0.011) and presence of VT on Holter (P=0.011) were significant in predicting failure of PVCs to suppress at peak heart rate on exercise testing. Syncope was not statistically significant in predicting suppression (P=0.18); however, CPVT was diagnosed in four patients with syncope during exercise. Quantity of PVCs, Lown grade, couplets on Holter, monomorphism, and PVC elimination at peak heart rate on Holter were not predictors of PVC suppression on exercise testing. Patients with syncope during exercise, family history of arrhythmia or SUD, or a Holter monitor showing VT warrant exercise testing to assess for CPVT.

Lidocaine bolus may facilitate computed tomographic coronary angiography in patients with frequent premature ventricular contractions

IntroductionHeart rate irregularities are the major limitations of computed tomographic coronary angiography (CTCA) due to severe motion artifacts.AimTo evaluate the safety and efficacy of a lidocaine intravenous bolus in preserving good image quality by the transient suppression of premature ventricular contractions (PVC) during the CTCA scan.Material and methodsThe study group comprised 67 consecutive patients with sinus rhythm and numerous PVC scheduled for CTCA. Intravenous boluses of 25–50 mg lidocaine were given after calcium score assessment and immediately before CTCA. The control group comprised 67 patients with sinus rhythm without PVC matched according to the body mass index (BMI), age, sex, and calcium score. All coronary vessel segments were assessed for image quality and presence of significant stenosis.ResultsAs compared with calcium score assessment, after administration of lidocaine and during the CTCA scan PVC were completely suppressed in 22 (40%), reduced in 10 (18%), unchanged in 18 (32%), and intensified in 5 (10%) patients. Overall, there were 32 (58%) patients with sinus rhythm during CTCA as compared with only 11 (20%) patients free from PVC during calcium score assessment (p < 0.001). Image quality in 871 coronary segments including both the study group and control patients was worse in patients with PVC (p < 0.0001). However, there was no statistically significant difference in the number of patients with at least one segment of non-diagnostic quality (6% vs. 12%, p = 0.36; respectively).ConclusionsSingle lidocaine bolus given prior to CTCA is safe, may temporarily eliminate or reduce the intensity of arrhythmia, and hence results in improved quality of CTCA in patients with numerous PVC.

628 Radiofrequency Catheter Ablation for Disabling Frequent Premature Ventricular Contractions: A Single-Center Experience

Radiofrequency (RF) ablation for frequent premature ventricular contractions (PVCs) has generally been performed in cases associated with tachycardiomyopathy. There are scant data concerning PVCs ablation only for disabling palpitations. Nineteen consecutive pts were included (47±18 years, 11 women). Left ventricular (LV) ejection fraction was 53±11% (<45% in 4 pts, of whom 2 with coronary artery disease). Seventeen pts presented with disabling palpitations (3 with syncope), 1 asymptomatic pt was ablated for mild LV enlargement, and 1 for family history of sudden cardiac death. Two pts had previous right ventricular (RV) outflow tract ventricular tachycardia (VT). Anti-arrhythmic drugs (AADs) were ineffective in 10 pts or associated with intolerance/side effects in 7, while 2 pts declined AADs for planned pregnancy. Mapping was performed in RV in 8 pts, in LV through retrograde access in 6 and through transseptal access in 2, and in both ventricles in 3. Post-ablation pts underwent 24h Holter recording within 3 months. Success was defined as ≥80% reduction in PVCs burden. Baseline PVCs burden on 24h Holter recording was 21±15%. In 13 pts, non-sustained VTs were also recorded. All pts were non-inducible for sustained VT during the procedure. In 4 pts, ablation was performed using solely pace-mapping (absent or rare PVCs). Voltage electronatomical mapping detected a zone of low-voltage/scar in the chamber of interest in 9 pts. PVCs location was in the RV in 8 pts (RV outflow tract in 7, para-hisian in 1), and in the LV in 11 (of whom LV outflow tract in 1, peri-mitral in 2, aortic cups in 1). Procedure and fluoroscopy times were 167±61 min and 15±8 min, respectively. Total RF application time was 9±6 min, and number of RF applications 11±7. Acute procedure completely suppressed PVCs in 13 pts, partially in 2, while there was no PVCs suppression in the remaining 4. PVCs burden decreased from 21±15% to 7±9% (p<0.001). During follow-up, success was achieved in 12 pts (63%). There were 3 minor complications: 2 pericardial effusions medically treated, and an arterio-venous fistula that did not require surgery. The only variable significantly correlated with success was the absence of polymorphic PVCs (≥2 morphologies). Success was achieved in 9/11 pts (82%) with monomorphic PVCs and in 3/8 pts (38%) with polymorphic PVCs (p=0.048). PVCs ablation for disabling symptoms is feasible and safe. Monomorphic PVCs are associated with better success rate compared to polymorphic PVCs.

Cardiomyopathy-inducing premature ventricular contractions: Not all animals are equal?

Isolated premature ventricular contractions (PVCs) are common in clinical practice and occur in patients with any form of structural heart and valvular disease as well as in normal hearts when they are usually considered benign. However, an improvement in the left ventricular (LV) systolic function after pharmacologic PVC suppression or ablation in patients with cardiomyopathy (CMP) 1,2 has led to the realization that frequent PVCs themselves sometimes can cause reversible LV dysfunction and PVC-induced CMP (PVC-CMP). At the first clinical encounter, patients often present with both PVCs and LV dysfunction, raising the question which condition came first. 3 Factors associated with the risk to develop PVC-CMP have been in the focus of intense investigations and include the PVC burden, duration of symptoms, QRS width, site of origin, and others. 4‐8 A significant overlap in these parameters usually exists between groups with and without PVC-CMP, limiting their prognostic utility. The current issue of HeartRhythm presents 2 retrospective studies examining the role of the PVC QRS duration on the development and regression of PVC-CMP. 7,9 Both studies used similar criteria to define PVC-CMP (ejection fraction [EF] 50%) and technical criteria for ablation success (80% PVC suppression) and had comparable PVC frequency in PVC-CMP groups (27%‐32%). Yokokawa et al 7 studied 294 patients with frequent PVCs referred for ablation. Of those, 113 were found to have a decreased LV EF. Other causes of CMP were excluded by thorough evaluation including cardiac magnetic resonance imaging (CMRI), rendering ventricular ectopy the only presumed cause of CMP. Patients with decreased LV function had longer PVC QRS duration than did those with normal LV EF (mean 164 ms vs 149 ms), and successful ablation resulted in the reversal of PVC-CMP in all cases. The study by Deyell et al 9 included 114 patients with frequent PVCs of which 48 had reduced LV EF. Longer PVC QRS duration also was associated with the presence of CMP. However, in a subgroup of patients with very wide PVCs (mean QRS duration 173 ms), successful suppression of PVCs failed to normalize LV function. There are several possible explanations for the difference in the study outcomes. First, some of the patients in the “irreversible” group of Deyell et al could have had a component of LV dysfunction unrelated to PVCs. (CMRI was not routinely performed in all patients but in 2 out of 3 patients in that group was abnormal.) Such patients would have been excluded by routine MRI screening in the study of Yokokawa et al. Of note, PVC frequency in the “irreversible” group was lower than in the “reversible” PVCCMP group, further suggesting that PVCs were an epiphenomenon.

Premature Ventricular Contraction-Induced Cardiomyopathy

Premature ventricular contractions (PVCs) are early depolarizations of the myocardium originating in the ventricle. They are often seen in association with structural heart disease and represent increased risk of sudden death,1 yet they are ubiquitous, even in the absence of identifiable heart disease.1,2 They may cause troubling and sometimes incapacitating symptoms such as palpitations, chest pain, presyncope, syncope, and heart failure.3 Traditionally, they have been thought to be relatively benign in the absence of structural heart disease.4,5 Over the last decade, however, PVC-induced cardiomyopathy has been a subject of great interest and the evidence for this entity is rapidly emerging. ### Epidemiology PVCs are common with an estimated prevalence of 1% to 4% in the general population.5 In a normal healthy population, PVCs have been detected in 1% of subjects on standard 12-lead electrocardiography and between 40% and 75% of subjects on 24- to 48-hour Holter monitoring.6 Their prevalence is generally age-dependent,1 ranging from 75 years.8 Commonly thought to be a benign entity,4,5 the concept of PVC-induced cardiomyopathy was proposed by Duffee et al9 in 1998 when pharmacological suppression of PVCs in patients with presumed idiopathic dilated cardiomyopathy subsequently improved left ventricular (LV) systolic dysfunction. Many of these patients often have no underlying structural heart disease and subsequently develop LV dysfunction and dilated cardiomyopathy; in cases of those with an already impaired LV function from underlying structural heart disease, worsening of LV function may occur.10,11 The exact prevalence of PVC-induced cardiomyopathy is not known; it is an underappreciated cause of LV dysfunction, and it is primarily observed in older patients.12 This observation could be due to the fact that the prevalence of …