Premature Ventricular Contractions Count Research Articles

The Diagnostic Utility of Holter Monitoring in Catecholaminergic Polymorphic Ventricular Tachycardia.

Holter monitoring may raise suspicion of an underlying catecholaminergic polymorphic ventricular tachycardia (CPVT) diagnosis. Although not a primary investigation for CPVT, Holter monitoring is ubiquitously used as a diagnostic tool in the heart rhythm clinic. The objective of this study was to explore Holter monitoring in CPVT diagnosis. This retrospective cohort study analyzed off-therapy Holter monitoring from 13 ryanodine receptor 2-positive CPVT and 34 healthy patients from the Canadian Hearts in Rhythm Organization national registry. Using the Edwards method, the ratio of ambient-maximum heart rate during Holter monitoring was correlated with exertion level to separate premature ventricular contractions (PVCs) during periods of adrenergic and nonadrenergic stress. A receiver operating characteristic curve analysis determined the optimal threshold for isolating CPVT-induced PVCs during adrenergic states. PVC burden differed between groups (P=0.001) but was within population norm, suggesting ambient PVCs are uncommon in CPVT. CPVT patients had higher PVC counts than healthy controls (P=0.002), with a different distribution based on adrenergic state. The optimal threshold for separating PVCs into periods of adrenergic and nonadrenergic stress in CPVT patients was 76% of the maximum heart rate during the monitoring period. Compared with healthy controls, CPVT patients had a higher PVC count, limited to periods of adrenergic stress, defined by >76% maximum heart rate threshold (P=0.002; area under the receiver operating characteristic curve: 0.84). Below this threshold, there was no significant PVC difference (P=0.604). Holter monitor PVC counts alone are inadequate for CPVT diagnosis, owing to the adrenergic nature of the disease. Quantifying PVC prevalence at a heart rate threshold >76% identified CPVT with moderate sensitivity (69%) and high specificity (94%).

Prognostic relevance of ventricular arrhythmias in surgical patients with gastrointestinal tumors.

Individuals diagnosed with gastrointestinal tumors are at an increased risk of developing cardiovascular diseases. Among which, ventricular arrhythmia is a prevalent clinical concern. This suggests that ventricular arrhythmias may have predictive value in the prognosis of patients with gastrointestinal tumors. To explore the prognostic value of ventricular arrhythmias in patients with gastrointestinal tumors receiving surgery. We retrospectively analyzed data from 130 patients undergoing gastrointestinal tumor resection. These patients were evaluated by a 24-h ambulatory electrocardiogram (ECG) at the Sixth Affiliated Hospital of Sun Yat-sen University from January 2018 to June 2020. Additionally, 41 general healthy age-matched and sex-matched controls were included. Patients were categorized into survival and non-survival groups. The primary endpoint was all-cause mortality, and secondary endpoints included major adverse cardiovascular events (MACEs). Colorectal tumors comprised 90% of cases. Preoperative ambulatory ECG monitoring revealed that among the 130 patients with gastrointestinal tumors, 100 (76.92%) exhibited varying degrees of premature ventricular contractions (PVCs). Ten patients (7.69%) manifested non-sustained ventricular tachycardia (NSVT). The patients with gastrointestinal tumors exhibited higher PVCs compared to the healthy controls on both conventional ECG [27 (21.3) vs 1 (2.5), P = 0.012] and 24-h ambulatory ECG [14 (1.0, 405) vs 1 (0, 6.5), P < 0.001]. Non-survivors had a higher PVC count than survivors [150.50 (7.25, 1690.50) vs 9 (0, 229.25), P = 0.020]. During the follow-up period, 24 patients died and 11 patients experienced MACEs. Univariate analysis linked PVC > 35/24 h to all-cause mortality, and NSVT was associated with MACE. However, neither PVC burden nor NSVT independently predicted outcomes according to multivariate analysis. Patients with gastrointestinal tumors exhibited elevated PVCs. PVCs > 35/24 h and NSVT detected by 24-h ambulatory ECG were prognostically significant but were not found to be independent predictors.

Prognostic implications of premature ventricular contractions and non-sustained ventricular tachycardia in light-chain cardiac amyloidosis.

Premature ventricular contractions (PVC) and non-sustained ventricular tachycardia (NSVT) are commonly observed in light chain cardiac amyloidosis (AL-CA), but their association with prognosis is still unclear. We aimed to evaluate the prognostic value of PVCs and NSVT in patients with moderate-to-advanced AL-CA. We retrospectively included patients with AL-CA at modified 2004 Mayo stages II-IIIb between February 2014 and December 2020. Twenty-four-hour Holter recordings were assessed on admission. The outcomes included (i) new onset of adverse ventricular arrhythmia (VA) or sudden cardiac death (SCD) and (ii) cardiac death during follow-up. Of the 143 patients studied (60.41 ± 11.06 years, male 64.34%), 132 (92.31%) had presence of PVC, and 50 (34.97%) had NSVT on Holter. Twelve (8.4%) patients died in hospital and 131 patients were followed up (median 24.4 months), among whom 71 patients had cardiac death, and 15 underwent adverse VA/SCD. NSVT [hazard ratio (HR): 13.57, 95% confidence interval (CI): 3.06-60.18, P < 0.001], log-transformed PVC counts (HR: 1.46, 95%CI: 1.15-1.86, P = 0.002) and PVC burden (HR: 1.43 95%CI:1.14-1.80, P = 0.002) were predictive of new onset of adverse VA/SCD. The highest tertile of PVC counts (HR: 2.33, 95%CI: 1.27-4.28, P = 0.006) and PVC burden (HR: 2.58, 95%CI: 1.42-4.69, P = 0.002), rather than NSVT (HR: 1.16, 95%CI: 0.67-1.98, P = 0.603), was associated with cardiac death. Higher PVC counts/burden provided incremental value on modified 2004 Mayo stage in predicting cardiac death, with C index increasing from 0.681 to 0.712 and 0.717, respectively (P values <0.05). PVC count, burden, and NSVT significantly correlated with adverse VA/SCD during follow-up in patients with AL-CA. Higher PVC counts/burdens added incremental value for predicting cardiac death.

Prognostic Significance of Different Ventricular Ectopic Burdens During Submaximal Exercise in Asymptomatic UK Biobank Subjects.

The consequences of exercise-induced premature ventricular contractions (PVCs) in asymptomatic individuals remain unclear. This study aimed to assess the association between PVC burdens during submaximal exercise and major adverse cardiovascular events (MI/HF/LTVA: myocardial infarction [MI], heart failure [HF], and life-threatening ventricular arrhythmia [LTVA]), and all-cause mortality. Additional end points were MI, LTVA, HF, and cardiovascular mortality. A neural network was developed to count PVCs from ECGs recorded during exercise (6 minutes) and recovery (1 minute) in 48 315 asymptomatic participants from UK Biobank. Associations were estimated using multivariable Cox proportional hazard models. Explorative studies were conducted in subgroups with cardiovascular magnetic resonance imaging data (n=6290) and NT-proBNP (N-terminal Pro-B-type natriuretic peptide) levels (n=4607) to examine whether PVC burden was associated with subclinical cardiomyopathy. Mean age was 56.8±8.2 years; 51.1% of the participants were female; and median follow-up was 12.6 years. Low PVC counts during exercise and recovery were both associated with MI/HF/LTVA risk, independently of clinical factors: adjusted hazard ratio (HR), 1.2 (1-5 exercise PVCs, P<0.001) and HR, 1.3 (1-5 recovery PVCs, P<0.001). Risks were higher with increasing PVC count: HR, 1.8 (>20 exercise PVCs, P<0.001) and HR, 1.6 (>5 recovery PVCs, P<0.001). A similar trend was observed for all-cause mortality, although associations were only significant for high PVC burdens: HRs, 1.6 (>20 exercise PVCs, P<0.001) and 1.5 (>5 recovery PVCs, P<0.001). Complex PVC rhythms were associated with higher risk compared with PVC count alone. PVCs were also associated with incident HF, LTVA, and cardiovascular mortality, but not MI. In the explorative studies, high PVC burden was associated with larger left ventricular volumes, lower ejection fraction, and higher levels of NT-proBNP compared with participants without PVCs. In this cohort of middle-aged and older adults, PVC count during submaximal exercise and recovery were both associated with MI/HF/LTVA, all-cause mortality, HF, LTVAs, and cardiovascular mortality, independent of clinical and exercise test factors, indicating an incremental increase in risk as PVC count rises. Complex PVC rhythms were associated with higher risk compared with PVC count alone. Underlying mechanisms may include the presence of subclinical cardiomyopathy.

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&amp;lt;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&amp;lt;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.

Association of serum electrolyte changes during haemodialysis with stimulation of premature ventricular contractions

BackgroundPatients on haemodialysis are predisposed to heart rhythm disorders, including bradyarrhythmia, atrial fibrillation (AF)/atrial flutter, supraventricular/ventricular arrhythmias and sudden cardiac death (SCD) (Turakhia et al. in Eur Heart J 39:2314–2325, 2018). In addition to the fact that patients on haemodialysis have a high prevalence of underlying cardiac disease, the stress of haemodialysis itself might also contribute to increased rates of arrhythmias and SCD (Samanta et al. in Can J Cardiol 35:1228–1240, 2019).MethodsA Holter 24-h electrocardiogram was set up immediately before the start of haemodialysis for 72 haemodialysis patients (dialysis vintage: 6–8734 days) to record premature ventricular contractions (PVCs) as a marker of arrhythmogenesis for 24 h. Blood samples were also collected every hour during haemodialysis treatment. Each patient was dialyzed against a dialysate consisting of Na+140 mEq/L, K+ 2.0 mEq/L, Ca+ 3.0 mEq/L, Mg2+ 1.0 mEq/L, Cl− 110 mEq/L, CH3COO− 8 mmol/L and HCO3− 30 mEq/L.ResultsThe frequency of PVCs significantly increased in the 4th (80 ± 34 beats/hour, mean ± S.E.), 5th (79 ± 31 beats/hour) and 6th (105 ± 36 beats/hour) hours (F = 5.24, p < 0.00001, n = 72). The lowest left ventricular ejection fraction (LVEF, p = 0.001) and the highest b-type natriuretic peptide (BNP) levels (p = 0.049) were found in patients with the highest PVC counts. There was an association of positive changes in both serum K+ (β ± S.E., 9.7 ± 2.4, p = 0.0002), Mg2+ (43.2 ± 10.3, p = 0.0001) and HCO3− (5.3 ± 1.8, p = 0.005) with the frequency of PVCs for 4 h immediately after dialysis. During the same period, there was an association of lower serum K+ (− 8.37 ± 2.16, p = 0.0003) and higher Ca2+ (73.4 ± 18.0, p = 0.0002) with the frequency of PVCs.ConclusionsHaemodialysis stimulated PVC generation, and this effect was especially prominent during the period immediately after haemodialysis. Some serum electrolyte changes affected this PVC stimulation. A positive change in serum K+ or Mg2+ and a negative change in serum Ca2+ during dialysis are risk factors for stimulating PVCs, particularly in patients with lower serum K+ or higher serum Ca2+ levels at the start of dialysis.

Acute Impact of Fine Particulate Air Pollution on Cardiac Arrhythmias in a Population-Based Sample of Adolescents: The Penn State Child Cohort.

Background Fine particulate (fine particles with aerodynamic diameters ≤2.5 μm [PM2.5]) exposure has been associated with a risk of cardiac arrhythmias in adults. However, the association between PM2.5 exposure and cardiac arrhythmias in adolescents remains unclear. Methods and Results To investigate the association and time course between PM2.5 exposure with cardiac arrhythmias in adolescents, we analyzed the data collected from 322 adolescents who participated in the PSCC (Penn State Child Cohort) follow-up examination. We obtained individual-level 24-hour PM2.5 concentrations with a nephelometer. Concurrent with the PM2.5 measure, we obtained 24-hour ECG data using a Holter monitor, from which cardiac arrhythmias, including premature atrial contractions and premature ventricular contractions (PVCs), were identified. PM2.5 concentration and numbers of premature atrial contractions/PVCs were summarized into 30-minute-based segments. Polynomial distributed lag models within a framework of a negative binomial model were used to assess the effect of PM2.5 concentration on numbers of premature atrial contractions and PVCs. PM2.5 exposure was associated with an acute increase in number of PVCs. Specifically, a 10 μg/m3 increase in PM2.5 concentration was associated with a 2% (95% CI, 0.4%-3.3%) increase in PVC counts 0.5 to 1.0, 1.0 to 1.5, and 1.5 to 2.0 hours after the exposure. Cumulatively, a 10 μg/m3 increment in PM2.5 was associated with a 5% (95% CI, 1%-10%) increase in PVC counts within 2 hours after exposure. PM2.5 concentration was not associated with premature atrial contraction. Conclusions PM2.5 exposure was associated with an acute increased number of ventricular arrhythmias in a population-based sample of adolescents. The time course of the effect of PM2.5 on ventricular arrhythmia is within 2 hours after exposure.

Frequent premature ventricular contractions. Association of burden and complexity with prognosis according to the presence of structural heart disease.

IntroductionPremature ventricular contractions (PVC) have been associated with mortality and heart failure (HF) regardless the presence of structural heart disease (SHD). The aim of this study was assessing the impact of burden and complexity of PVCs on prognosis, according to presence of SHD.Methods312 patients were retrospectively evaluated out of 1967 consecutive patients referred for 24‐hr Holter at a single hospital, with a PVC count >1% of total beats. Two groups with and without SHD. PVC burden (PVC%), presence of complex forms, incidence of all‐cause death, combined outcomes of all‐cause death and cardiovascular hospitalizations, HF death and HF hospitalizations and, sudden death (SD) or hospitalizations due to ventricular arrhythmias (VA)were assessed.ResultsPremature ventricular contraction burden was 2.7 (IQR: 1.6–6.7). SHD patients had more polymorphic PVCs, 77% versus 65%, p = .022, triplets and episodes of non‐sustained ventricular tachycardia (NSVT): 44% versus 27%, p = .002; 30% versus 12%, p < .0001. In idiopathic patients, a PVC% in the third quartile was independently associated with all‐cause mortality hazard ratio (HR) 2.288 (1.042–5.026) p = .039, but not in SHD. The complexity of the PVCs was not independently associated with outcomes in both groups. In SHD group, NSVT was associated with lower survival free from SD and VA hospitalizations, p = .028; after multivariable, there was a trend for a higher arrhythmic outcome with NSVT, HR 3.896 (0.903–16.81) p = .068.ConclusionPremature ventricular contractions in SHD showed more complex patterns. In idiopathic patients, a higher PVC count was associated with higher mortality but not is SHD patients. Complexity was not independently associated with worse prognosis.

Oral caffeine intake amplifies the effect of isoproterenol in patients with frequent premature ventricular contractions.

Infrequent appearance and failed induction of premature ventricular contractions (PVCs) at catheter ablation make their localization difficult and are associated with a poor procedural outcome. This study aimed to assess the effect of preprocedural oral caffeine intake on induction of PVCs during catheter ablation. Seventy patients (age: 54 ± 14 years, 37 men) undergoing catheter ablation for monofocal PVCs were randomized to receive oral caffeine (5 mg/kg) or placebo. Before ablation, PVC counts for 5 min were performed at baseline and during isoproterenol infusion and the isoproterenol washout period. PVC count fluctuation was defined as the difference between the highest and lowest 5-min count among the three-time periods. The 5-min PVC counts during baseline and isoproterenol infusion were equivalent between the groups. However, those during the isoproterenol washout period and PVC count fluctuation were significantly higher in the caffeine group than the control group (73.1 ± 73.2 vs. 38.9 ± 28.9 beats/5 min, P = 0.012 and 69.3 ± 61.3 vs. 37.7 ± 30.9 beats/5 min, P = 0.008, respectively). The procedure and ablation times were significantly shorter in the caffeine group than the control group (105.0 ± 23.4 vs. 136.9 ± 43.2 min, P < 0.01 and 219.1 ± 104.7 vs. 283.5 ± 136.0 sec, P < 0.01, respectively). Oral caffeine intake amplified the effect of isoproterenol infusion on PVC induction during catheter ablation. The combined use of oral caffeine intake and isoproterenol infusion can be an option to increase intraprocedural PVCs.

P3754Comparison of the transdermal bisoprolol patch with the oral bisoprolol fumarate administration as a therapeutic agent for idiopathic frequent premature ventricular contractions

Abstract Background The transdermal bisoprolol patch (TB) was designed to maintain a sustained concentration of bisoprolol in plasma by higher trough concentration than the oral bisoporolol fumarate administration (OB). It is unclear whether the TB is as effective in treating idiopathic premature ventricular contractions (PVCs) as the OB. Purpose We compared the efficacy between the TB and OB in treating idiopathic PVCs while considering their duration of action. Methods Among 198 patients with a PVC count of ≥3,000 beats/24 hours, 84 patients were divided into groups treated with TB 4mg (n=50) or OB 2.5mg (n=34). The PVCs were divided into positive heart rate (HR)-dependent PVCs (P-PVCs) and non-positive HR-dependent PVCs (NP-PVCs) based on the relationship between the hourly PVCs density and hourly mean HR. To evaluate the efficacy, PVC counts by 24-hour Holter electrocardiograms were measured at baseline and at 1 month after the initiation of the therapy. Results There were no significant between-group differences for the mean HR, PVC count, or type of PVCs. Both the TB (from 16,692±9,737 to 10,442±10,711 beats/24 hours, P&lt;0.001) and OB (from 19,633±16,298 to 9,235±12,124 beats/24 hours, P&lt;0.001) significantly decreased the total PVC count after the initiation of therapy, and a comparison between the two drugs showed no significant difference (P=0.46). In the P-PVC group, both the TB and OB significantly decreased the total PVC count (P&lt;0.001, P=0.022 respectively), PVC count during the day-time (P&lt;0.001, P=0.030 respectively), and PVC count during the night-time (P=0.0038, P=0.022 respectively). In contrast, in the NP-PVC group, neither the TB nor OB made any significantly change in the total PVC count (P=0.079, P=0.10 respectively), PVC count during the day-time (P=0.35, P=0.12 respectively), or PVC count during the night-time (P=0.11, P=0.12 respectively). The TB exhibited a significant reduction during each time period regarding the changes within 24-hours in the P-PVC count from baseline, while the OB did not significantly reduce the P-PVC count from baseline during each time period between 0 and 5 o'clock. Conclusions Compared with the OB, the TB could be used with the same efficacy for reducing the PVC count. The TB could be a more useful therapeutic agent for idiopathic P-PVCs during a 24-hour period than the OB.

Excessive Atrial Ectopic Activity Worsens Prognosis and Predicts the Type of Major Adverse Cardiac Events in Patients With Frequent Premature Ventricular Contractions.

BackgroundThe aim of the study was to evaluate the impact of premature atrial contractions (PACs) burden, and the presence of non-sustained ventricular tachycardia (NSVT) on prognosis and type of major adverse cardiovascular events in patients with frequent premature ventricular contractions (PVCs).MethodsWe retrospectively studied 285 consecutive patients with frequent PVCs defined as PVC count equal or higher than 1% of total beats assessed with 24-h Holter recording. Patients with atrial fibrillation (AF) were excluded. We evaluated the impact of PAC burden and the presence of NSVT on the primary end points of all-cause mortality, stroke and new-onset AF, and secondary end points; arrhythmic end point (arrhythmic death or hospitalizations for ventricular arrhythmias) or heart failure (HF)-related end point (death or hospitalizations due to HF).ResultsThe PAC number showed an adjusted hazard ratio (HR) (95% confidence interval (CI), P value) of 1.077 (1.014 - 1.145, P = 0.017) for all-cause mortality, 1.250 (1.080 - 1.447, P = 0.003) for stroke, 1.090 (1.006 - 1.181, P = 0.036) for new-onset AF and 1.376 (1.128 - 1.679, P = 0.002) for the HF end point. The presence of NSVT showed an adjusted HR (95% CI) of 3.644 (1.147 - 11.57, P = 0.028) for the arrhythmic end point.ConclusionsIn patients with frequent PVCs a high PAC count was independently associated with increased mortality, higher rate of AF, stroke and HF adverse events, but not with arrhythmic adverse events. The presence of NSVT was independently associated with increased arrhythmic adverse events, but not with overall mortality, AF, stroke or HF events.

ECG morphology of premature ventricular contractions predicts the presence of myocardial fibrotic substrate on cardiac magnetic resonance imaging in patients undergoing ablation.

The most likely origin of premature ventricular contractions (PVCs) may be deduced from surface electrocardiogram (ECG) analysis while planning an electrophysiological study (EPS). Apart from purely benign forms of increased ventricular ectopy, myocardial substrate (e.g., regional fibrosis) may be present in certain cases, which will significantly impact the ablation approach. Cardiac magnetic resonance (CMR) imaging can reliably identify fibrotic target lesions and, hence, may assist in adequate patient selection and procedural planning. We analyzed 101 patients (59% males, mean age 57.15 ± 15.5 years, mean PVC count 19,801 ± 14,021 per 24 hours) referred for ablation of PVCs. The CMR (1.5T, Philips Ingenia, Best, The Netherlands) protocol included cine and three-dimensional-delayed enhancement imaging using standard cardiac geometries. On surface, ECG right bundle branch block (RBBB) morphology was present in 43% of patients. Twenty-one patients showed the fibrotic substrate on CMR. On univariate analysis, both RBBB morphology (P<0.001) and presence of multiple PVC morphologies (≥2) significantly predicted the presence of fibrotic substrate (P=0.01), which various baseline characteristics including left ventricular ejection fraction (45.7 ± 12.6% vs. 50.6 ± 11.0%, P=0.08) failed to do. CMR-identified fibrosis was associated with the site of origin of the clinical PVCs during EPS and was successfully treated by radiofrequency ablation in 93% (PVC reduction>95%). In patients with RBBB morphology and/or multiple PVC patterns, CMR imaging before ablation may be helpful due to the increased prevalence of fibrotic lesions with regard to patient stratification and periprocedural management.

Assessment of a novel transdermal selective β1-blocker, the bisoprolol patch, for treating frequent premature ventricular contractions in patients without structural heart disease

BackgroundThe autonomic nervous system involves the genesis of premature ventricular contractions (PVCs). Previous studies demonstrated that heart rate (HR) dependency of idiopathic PVCs has different autonomic mechanisms. Recently, the bisoprolol patch, a novel transdermal β1-blocker formulation containing bisoprolol, became clinically available. We examined the efficacy of the bisoprolol patch for treating frequent PVCs in patients without structural heart disease (SHD) regarding the HR dependency of PVCs. MethodsThis prospective study included 44 consecutive patients without SHD (25 men, mean age, 63.6±12.3 years) with PVC counts≥3000 beats as measured by 24-hour Holter electrocardiograms (ECGs). PVCs were divided into positive HR-dependent PVCs (P-PVCs) and non-positive HR-dependent PVCs (NP-PVCs) based on the relationship between the hourly PVC density and hourly mean HR. A bisoprolol patch was administered once daily at a dose of 4mg. The 24-hour Holter ECGs were performed before and 1 month after the initiation of the therapy. ResultsIn 44 patients, there were 24 P-PVCs and 20 NP-PVCs. The bisoprolol patch reduced the PVC count significantly (from 16,563±10,056 to 7892±8817 beats/24hours, p<0.001) in the P-PVC group, while the PVC count did not change significantly (from 16,409±9571 to 13,476±12,191beats/24hours, p=0.34) in the NP-PVC group. Moreover, in the P-PVC group, the patients with mean HRs ≥80 beats/minute had a significantly higher percent improvement in the PVC count than those with mean HRs <80 beats/minute (p=0.0080). The bisoprolol patch resulted in a significant reduction in the PVC count from baseline during each time period for the changes within a 24-hour period in the P-PVC group. ConclusionsThe transdermal bisoprolol patch was effective for a PVC reduction in patients with P-PVCs, particularly in those with faster mean HRs. Furthermore, it demonstrated a stable PVC-reducing effect during the 24-hour period in the P-PVC group.

Ranolazine is an Effective and Safe Treatment of Adults with Symptomatic Premature Ventricular Contractions due to Triggered Ectopy.

Early and delayed afterdepolarizations (EAD/DAD) cause triggered ventricular ectopy. Because ranolazine (RAN) suppresses EAD/DAD, we postulated that RAN might be effective in reducing premature ventricular contractions (PVCs). To assess the effect of RAN in patients with symptomatic PVCs due to triggered ectopy and its safety and tolerability. A total of 59 patients with symptomatic PVCs were identified from full-disclosure Holters. Doses of 500 and 1,000 mg offlabel RAN, daily, were given to 34 and 66% patients, respectively, and repeat Holters were performed prospectively during mean followup of 3.1 months. The two Holters were retrospectively compared. Congestive heart failure (CHF) was defined as symptoms including dyspnea, orthopnea, paroxysmal nocturnal dyspnea, and fatigue, with a brain natriuretic peptide > 400. Systolic (heart failure with reduced ejection fraction) versus diastolic (heart failure with preserved ejection fraction, HFpEF) CHF depended upon an echocardiographic left ventricular ejection fraction (LVEF) at least 50% by apical two- and four-chamber Simpson's method (HFpEF). The mean age of the patients was 63 years, 60% were males, mean left ventricular ejection fraction was 60%, with 34% having coronary artery disease, 73% were hypertensive, 24% had type 2 diabetic, and 34% were on beta blockers. Upon repeat Holters at a mean of 3.1 months after initiating RAN, 95% (56/59) of the patients had their PVC count reduced as follows: 24% (14/59) had more than 90% decrease, 34% (20/59) had 71 to 90% decrease, and 17% (10/59) had 50 to 70% decrease. In the entire group, RAN reduced PVCs by 71% (mean: 13,329 to 3,837; p < 0.001). Ventricular bigeminy was reduced by 80% (4,168 to 851; p < 0.001), ventricular coupletswere reduced by 78% (374 to 81; p < 0.001), and ventricular tachycardiawas reduced by 91% (56 to 5; p < 0.001). The PVC reduction was dose dependent. Off-label RAN offers an effective and safe pharmacologic treatment for symptomatic triggered PVCs. A large, prospective randomized study is needed.

Longer Ambulatory ECG Monitoring Increases Identification of Clinically Significant Ectopy.

Frequent premature ventricular contractions (PVCs) can cause a reversible reduction in systolic function. Most studies use 24-hour ambulatory electrocardiograms (AECGs) to assess PVC burden; however, PVC counts vary across 24-hour periods. We hypothesized that extended AECG monitoring would better identify clinically significant ectopy. All 14-day AECGs performed at the San Francisco Veterans Affairs Medical Center between 2012 and 2015 (N = 694) were reviewed, and individuals with PVC counts ≥1.0% of total heartbeats were included (N = 101). Daily PVC counts and the range of these values across 24-hour periods were assessed. Median time for these ranges to cross clinically significant thresholds (PVCs ≥ 10%, 15%, or 20% of total heartbeats) was determined. Median PVC burden was 2.6% of total heartbeats (interquartile range [IQR]: 1.6-5.4%) and the median range across 24-hour periods was 3.6% (IQR: 2.0-9.1%). Individual ranges of daily PVC burden crossed thresholds of 10%, 15%, and 20% of total heartbeats in 26.7%, 16.8%, and 6.9% of patients, respectively. Median time to detecting an individual's maximum PVC burden was 6 days (IQR: 2-11 days). While 75% of those who reached the 20% threshold did so on day one of monitoring, only 53% of those reaching the 10% threshold did similarly, with a continually increasing yield throughout the 14-day monitoring period. PVC burden varies widely from day-to-day. While most patients with PVC burdens ≥20% were detected with 24 hours of monitoring, extended monitoring nearly doubled the identification of those reaching the 10% threshold.

Abstract P008: Repeatability of Ectopic Beats From 48-hour Ambulatory Electrocardiography: The Atherosclerosis Risk in Communities (ARIC) Study

Background: Ectopic beats, defined by premature atrial contractions (PACs) and premature ventricular contractions (PVCs), are one of the most common findings on the electrocardiogram (ECG). Excess ectopic beats on ambulatory ECG monitoring are associated with atrial fibrillation (AF), stroke and death in symptomatic patients and in population-based studies. However, the repeatability of ECG-enumerated ectopic beats has not been sufficiently examined in a general population. Objectives: Characterize the repeatability of PACs and PVCs in a community-based population of older adults. Methods: Ambulatory, 48-hour ECG was measured in a subsample of the Atherosclerosis Risk in Communities Study (ARIC; 2011-2013) at two locales. Participants were randomly invited to participate in the repeatability study (n=92). Following an identical, standardized protocol, the participants wore a Holter monitor for two, 48-hour periods separated by a mean of 38 days (range: 11, 130 days) and completed a symptom questionnaire during each period. Each visit included new electrodes and Holter placement. All participants wore monitors for 48 hours and had recordings with &lt;1% noise. Participants with AF (n=4) or paced rhythm (n=2) were excluded (total n=86; mean age 74.6 years; 56 females, 55 black). Visit-specific quartiles and 80th percentile cut-points for the total counts of PACs and PVCs over the 48 hour monitoring period were used. Between-visit agreement was quantified using the weighted kappa for quartiles and kappa for 80th percentile cut-points. Results: About 17% of the participants reported symptoms of dizziness, palpitations, or chest pain while wearing the monitor. During the 48-hour recordings, all participants had ≥1 PAC count and 2 participants had a 0 PVC count. The overall median (interquartile range (IQR)) was 266 counts (IQR: 80, 1,692.5) for PACs and 223 counts (IQR: 17.5, 1,085.5) for PVCs. The median between-visit difference (visit 2 - visit 1) was -12.5 counts for PACs (IQR: -154, 65) and 0 counts for PVCs (IQR: -78, 320). The between-visit, weighted kappa for count quartiles was 0.70 (95% confidence interval (CI): 0.61, 0.80) for PACs and 0.68 (95% CI: 0.58, 0.78) for PVCs. The kappa for counts &gt;80th percentile was 0.56 (95% CI: 0.34, 0.78) for PACs and 0.71 (95% CI: 0.52, 0.90) for PVCs. Conclusion: Between-visit agreement is high to moderate for 48-hour, Holter-based PACs and PVCs quantiles, according to common interpretations for kappa coefficients. When paired with pending examination of how agreement varies over shorter duration recordings within the 48-hour monitoring period, the present results can facilitate epidemiologic and clinical applications in which knowledge of measurement error, variability and misclassification are needed to inform risk assessment.

Abstract 18409: Longer Ambulatory Monitoring Increases Identification of Clinically Significant Ectopy

Introduction: Frequent premature ventricular contractions (PVCs) can cause a reversible reduction in left ventricular systolic function. Prior studies have found that this cardiomyopathy is associated with PVC counts exceeding 13-37% of total heart beats. Most of these studies used 24-hour ambulatory electrocardiograms (AECG) to assess PVC burden; however, PVC counts may vary across 24-hour periods. Hypothesis: Extended monitoring with AECG will improve detection of clinically significant ectopy. Methods: Records from all patients receiving 14-day AECGs at the San Francisco Veterans Affairs Medical Center between March 2012 and March 2015 (N=694) were reviewed and those with total PVC counts ≥ 1.0% of total heart beats were included (N= 105). Each patient’s daily PVC count was abstracted, and the range of these values across 24-hour periods was assessed. The median time for these ranges to cross clinically significant thresholds (PVCs ≥ 10, 15 or 20% of total heart beats) was determined. Results: Median PVC burden was 2.8% of total heart beats (interquartile range, IQR 1.8-6.8%) and the median range across 24-hour periods was 4.7% (IQR 2.9-10.4%). Individual ranges of daily PVC burden crossed thresholds of 10, 15 and 20% of total heart beats in 23.8%, 17.1% and 12.4% of patients, respectively. Median time to detecting an individual’s maximum PVC burden was 6 days (IQR 2-11 days). While 88% of those who reached the 20% threshold did so on the first day of monitoring, only 53% of those reaching the 10% threshold did similarly, with a continually increasing yield throughout the 14 day monitoring period (Figure). Conclusions: Individual PVC burden varies widely from day-to-day. While the majority of patients who ultimately crossed clinically significant thresholds did so on the first day of monitoring, extended monitoring nearly doubled those reaching the 10% threshold.

Premature ventricular contraction variability in arrhythmogenic right ventricular dysplasia/cardiomyopathy.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an inherited cardiomyopathy, characterized by right ventricular dysfunction and ventricular arrhythmias. Premature ventricular contractions (PVCs) are an important measure in determining disease severity and constitute a minor criterion in the 2010 Task Force Criteria for the diagnosis of ARVD/C. Little information is available regarding the variability in PVCs. Patients (n = 40) from the Johns Hopkins ARVD/C registry, meeting diagnostic criteria were included. Single lead continuous 12-lead electrocardiogram (ECG) monitors (Zio® Patches) were applied to monitor PVC counts. Detailed demographic, phenotypic, and structural information were obtained from registry data. ECG monitors were worn for a mean period of 159.3 hours (±39.3). Average 24-hour PVC count in this population was 1,090.5 (interquartile range = 1,711). One-way analysis of variance demonstrated statistically significant interday variance in mean hourly PVC counts in 76% of ARVD/C-positive subjects (28/37, 3 cases excluded due to insufficient data). Eleven individuals (27.5%) had maximum 24-hour PVC counts of >500 with a corresponding minimum 24-hour PVC count of <500. The average 24-hour PVC count for each patient was derived for each day recorded. The 24-hour PVC count placed 89.6% of counts (223/249) on the correct side of the 500-PVC count. Statistically significant variation between 24-hour PVC counts is present in the ARVD/C population. However, 24-hour ECG monitoring was sufficient to identify 89.6% of 24-hour periods to the correct grouping based on 2010 Task Force Criteria.

Local dynamics of heart rate: detection and prognostic implications

The original observation that reduced heart rate variability (HRV) confers poor prognosis after myocardial infarction has been followed by many studies of heart rate dynamics. We tested the hypothesis that an entropy-based local dynamics measure gave prognostic information in ambulatory patients undergoing 24-h electrocardiography. In this context, entropy is the probability that short templates will find matches in the time series. We studied RR interval time series from 24-h Holter monitors of 1564 consecutive patients over age 39. We generated histograms of the count of templates as a function of the number of templates matches in short RR interval time series, and found characteristic appearance of histograms for atrial fibrillation, sinus rhythm with normal HRV, and sinus rhythm with reduced HRV and premature ventricular contractions (PVCs). We developed statistical models to detect the abnormal dynamic phenotype of reduced HRV with PVCs and fashioned a local dynamics score (LDs) that, after controlling for age, added more prognostic information than other standard risk factors and common HRV metrics, including, to our surprise, the PVC count and the HRV of normal-to-normal intervals. Addition of the LDs to a predictive model using standard risk factors significantly increased the ROC area and the net reclassification improvement was 27%. We conclude that abnormal local dynamics of heart rate confer adverse prognosis in patients undergoing 24-h ambulatory electrocardiography.