Abstract
Aims
The aim of this study was to determine electrocardiographic (ECG) criteria predicting abnormal infrahissian conduction in patients with myotonic dystrophy type 1 (DM1), as these ...criteria could be used to identify the need for an electrophysiological study (EPS).
Methods and results
A retrospective multicentre study was conducted including DM1-affected individuals who underwent EPS between 2007 and 2018. For each individual, EPS indication, His-ventricle (HV) interval, resting ECG parameters prior to EPS, left ventricular ejection fraction (LVEF), neurological status, and DM1 DNA analysis results were collected. Electrocardiographic parameters of patients with a normal HV interval were compared with ECG parameters of patients with a prolonged HV interval. Logistic regression was performed to determine predictors for a prolonged HV interval of ≥70 ms on EPS and diagnostic accuracy of ECG parameters was ascertained. Among 100 DM1-affected individuals undergoing EPS, 47 had a prolonged HV interval. The sole presence of a PR interval >200 ms odds ratio (OR) 8.45, confidence interval (CI) 2.64–27.04 or a QRS complex >120 ms (OR 9.91, CI 3.53–27.80) on ECG were independent predictors of a prolonged HV interval. The combination of both parameters had a positive predictive value of 78% for delayed infrahissian conduction on EPS. His-ventricle interval was independent of DM1 genetic mutation size, neuromuscular status, and LVEF.
Conclusion
The combination of a prolonged PR interval and widened QRS complex on ECG accurately predicts abnormal infrahissian conduction on EPS in patients with DM1. These ECG parameters could be used as a screening tool to determine the need for referral to a specialized multidisciplinary neuromuscular team with EPS capacity.
Background Idiopathic ventricular fibrillation (IVF) is diagnosed in patients with ventricular fibrillation of which the origin is not identified after extensive evaluations. Recent studies suggest ...an association between mitral annulus disjunction (MAD), mitral valve prolapse (MVP), and ventricular arrhythmias. The prevalence of MAD and MVP in patients with IVF in this regard is not well established. We aimed to explore the prevalence of MAD and MVP in a consecutive cohort of patients with IVF compared with matched controls. Methods and Results In this retrospective, multicenter cohort study, cardiac magnetic resonance images from patients with IVF (ie, negative for ischemia, cardiomyopathy, and channelopathies) and age‐ and sex‐matched control subjects were analyzed for the presence of MAD (≥2 mm) and MVP (>2 mm). In total, 72 patients (mean age 39±14 years, 42% women) and 72 control subjects (mean age 41±11 years, 42% women) were included. MAD in the inferolateral wall was more prevalent in patients with IVF versus healthy controls (7 11% versus 1 1%, P =0.024). MVP was only seen in patients with IVF and not in controls (5 7% versus 0 0%, P =0.016). MAD was observed in both patients with (n=4) and without (n=3) MVP. Conclusions Inferolateral MAD and MVP were significantly more prevalent in patients with IVF compared with healthy controls. The authors advocate that evaluation of the mitral valve region deserves extra attention in the extensive screening of patients with unexplained cardiac arrest. These findings support further exploration of the pathophysiological mechanisms underlying a subset of IVF that associates with MAD and MVP.
Background The objective of this international multicenter study was to investigate both early and late outcomes of cardiac resynchronization therapy (CRT) in patients with a systemic right ventricle ...(SRV) and to identify predictors for congestive heart failure readmissions and mortality. Methods and Results This retrospective international multicenter study included 13 centers. The study population comprised 80 adult patients with SRV (48.9% women) with a mean age of 45±14 (range, 18-77) years at initiation of CRT. Median follow-up time was 4.1 (25th-75th percentile, 1.3-8.3) years. Underlying congenital heart disease consisted of congenitally corrected transposition of the great arteries and dextro-transposition of the great arteries in 63 (78.8%) and 17 (21.3%) patients, respectively. CRT resulted in significant improvement in functional class (before CRT: III, 25th-75th percentile, II-III; after CRT: II, 25th-75th percentile, II-III;
=0.005) and QRS duration (before CRT: 176±27; after CRT: 150±24 milliseconds;
=0.003) in patients with pre-CRT ventricular pacing who underwent an upgrade to a CRT device (n=49). These improvements persisted during long-term follow-up with a marginal but significant increase in SRV function (before CRT; 30%, 25th-75th percentile, 25-35; after CRT: 31%, 25th-75th percentile, 21-38;
=0.049). In contrast, no beneficial change in the above-mentioned variables was observed in patients who underwent de novo CRT (n=31). A quarter of all patients were readmitted for heart failure during follow-up, and mortality at latest follow-up was 21.3%. Conclusions This international experience with CRT in patients with an SRV demonstrated that CRT in selected patients with SRV dysfunction and pacing-induced dyssynchrony yielded consistent improvement in QRS duration and New York Heart Association functional status, with a marginal increase in SRV function.
Abstract Fragmented QRS complexes (fQRS) on 12-lead electrocardiogram are known predictors of ventricular tachyarrhythmia (VTA) in patients with coronary artery disease. There is limited knowledge of ...the clinical implications of fQRS in patients with congenital heart defects (CHD). Aims of this study were to examine 1) the occurrence of fQRS in patients with various types of CHD and 2) whether fQRS is associated with development of VTA. This study was designed as retrospective case-control study. CHD patients with VTA were included and matched with control patients of the same age, gender and CHD type Clinical data and fQRS were analysed and compared. The initial VTA episode developed in 139 CHD patients at a mean age of 39±14years. Compared to controls (N=219, age 38±13 years), QRS-duration was longer in VTA patients (110ms vs 100; p<0.01). Furthermore, fQRS was more frequently observed in VTA patients in the last ECG prior to VTA (N=73 (53%) vs N=67 (31%); p<0.001); especially in patients with sustained VTA (64%). Multiple conditional logistic regression demonstrated more fQRS (OR 2.9, 95% CI 1.5–5.8; p=0.002), non-systemic ventricular dysfunction (OR 5.1, 95% CI 2.1–12.4; p<0.001) and more prolonged QRS complexes (OR 2.8, 95% CI 1.3–6.2; p=0.011) in VTA patients. Therefore, the presence of fQRS on ECG may be a useful tool in daily clinical practice to identify patients at risk for developing VTA in patients with CHD, in addition to known predictors of VTA.
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is rarely diagnosed in childhood. We describe the case of a 9-year-old girl with genetically confirmed ARVC who presented with syncope, ...ventricular arrhythmia, and biventricular myocardial dysfunction. This case highlights the need for development of pediatric ARVC diagnosis criteria specific for pediatric patients and discusses potential diagnostic improvement using echocardiographic deformation imaging. (Level of Difficulty: Beginner.)
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Arrhythmogenic right ventricular cardiomyopathy (ARVC) is rarely diagnosed in childhood. We describe the case of a 9-year-old girl with genetically…
Electrocardiographic (ECG) fusion with intrinsic QRS could reduce the benefit of atrial synchronous biventricular pacing (AS-BiVP) in patients with hypertrophic obstructive cardiomyopathy (HOCM).
The ...purpose of this study was to assess the benefit of AS-BiVP and the influence of ECG fusion for reduction of left ventricular outflow tract gradient (LVOTG) in these patients.
Twenty-one symptomatic HOCM patients with severe LVOTG were included. Twelve patients were evaluated retrospectively for the prevalence of fusion and its influence on outcomes after AS-BiVP. Eleven patients (2 of the first population were also evaluated retrospectively) were prospectively included to evaluate the benefit of performing atrioventricular node ablation (AVNA) to achieve full ventricular capture if fusion was present during AS-BiVP.
Seven of the first 12 patients (58%) had ECG fusion. After 54 ± 24 months of AS-BiVP, the presence of fusion was associated with lower values for reduction of resting, dynamic LVOTG and New York Heart Association (NYHA) class. In the prospectively evaluated patients, after 12 months of follow-up, resting LVOTG decreased from 98 ± 39 to 39 ± 24 mm Hg (P = .008); dynamic LVOTG decreased from 112 ± 38 to 60 ± 24 mm Hg (P = .013); NYHA class decreased from 2.8 ± 0.4 to 1.7 ± 0.6 (P = .014); endurance time during constant work rate cycling exercise (80% of peak oxygen consumption) increased from 399 ± 148 to 691 ± 249 seconds (P = .046); quality of life improved from 46 ± 22 to 22 ± 20 points (P = .02); and brain natriuretic peptide levels decreased from 318 ± 238 to 152 ± 118 pg/mL (P = .09). Eight of the 11 prospectively evaluated patients (73%) needed AVNA, which further decreased LVOTG from 108 ± 40 mm Hg at baseline to 89 ± 29 mm Hg after BiVP to 54 ± 22 mm Hg after AVNA (P = .003).
As-BiVP that ensures no ECG fusion, by means of AVNA when needed, appears to be the optimal pacing mode in HOCM patients.
Direct Evidence for Insulin-Induced Capillary Recruitment in Skin of Healthy Subjects During Physiological Hyperinsulinemia
Erik H. Serné 1 2 ,
Richard G. IJzerman 1 2 ,
Reinold O.B. Gans 3 ,
Robin ...Nijveldt 1 ,
Greetje de Vries 1 ,
Reinder Evertz 1 ,
Ab J.M. Donker 1 2 and
Coen D.A. Stehouwer 1 2
1 Department of Medicine, Academic Hospital Vrije Universiteit, Amsterdam, the Netherlands
2 Institute for Cardiovascular Research-Vrije Universiteit, Amsterdam, the Netherlands
3 Department of Medicine, University Hospital Groningen, Groningen, the Netherlands
Abstract
It has been proposed that insulin-mediated changes in muscle perfusion modulate insulin-mediated glucose uptake. However,
the putative effects of insulin on the microcirculation that permit such modulation have not been studied in humans. We examined
the effects of systemic hyperinsulinemia on skin microvascular function in eight healthy nondiabetic subjects. In addition,
the effects of locally administered insulin on skin blood flow were assessed in 10 healthy subjects. During a hyperinsulinemic
clamp, we measured leg blood flow with venous occlusion plethysmography, skin capillary density with capillaroscopy, endothelium-(in)dependent
vasodilatation of skin microcirculation with iontophoresis of acetylcholine and sodium nitroprusside combined with laser Doppler
fluxmetry, and skin vasomotion by Fourier analysis of microcirculatory blood flow. To exclude nonspecific changes in the hemodynamic
variables, a time-volume control study was performed. Insulin iontophoresis was used to study the local effects of insulin
on skin blood flow. Compared to the control study, systemic hyperinsulinemia caused an increase in leg blood flow (−0.54 ±
0.93 vs. 1.97 ± 1.1 ml · min −1 · dl −1 ; P < 0.01), an increase in the number of perfused capillaries in the resting state (−3.7 ± 3.0 vs. 3.4 ± 1.4 per mm 2 ; P < 0.001) and during postocclusive reactive hyperemia (−0.8 ± 2.2 vs. 5.1 ± 3.7 per mm 2 ; P < 0.001), an augmentation of the vasodilatation caused by acetylcholine (722 ± 206 vs. 989 ± 495%; P < 0.05) and sodium nitroprusside (618 ± 159 vs. 788 ± 276%; P < 0.05), and a change in vasomotion by increasing the relative contribution of the 0.01- to 0.02-Hz and 0.4- to 1.6-Hz spectral
components ( P < 0.05). Compared to the control substance, locally administered insulin caused a rapid increase (∼13.5 min) in skin microcirculatory
blood flow (34.4 ± 42.5 vs. 82.8 ± 85.7%; P < 0.05). In conclusion, systemic hyperinsulinemia in skin 1 ) induces recruitment of capillaries, 2 ) augments nitric oxide−mediated vasodilatation, and 3 ) influences vasomotion. In addition, locally administered insulin 4 ) induces a rapid increase in total skin blood flow, independent of systemic effects.
Footnotes
Address correspondence and reprint requests to Dr. C.D.A. Stehouwer, Department of Medicine, Academic Hospital Vrije Universiteit,
De Boelelaan 1117, P.O. Box 5057, 1007 MB, Amsterdam, the Netherlands. E-mail: cda.stehouwer{at}vumc.nl .
Received for publication 17 January 2001 and accepted in revised form 15 February 2002.
CV, coefficient of variation; DBP, diastolic blood pressure; M, whole-body glucose uptake; MAP, mean arterial pressure; M/I,
whole-body glucose uptake per unit of plasma insulin concentration; PRH, postocclusive reactive hyperemia; PU, arbitrary perfusion
units.
DIABETES
The ventricular tachycardia (VT) monitoring zone in implantable cardioverter defibrillators (ICDs) is usually programmed to detect slow VTs. However, it is not well known whether programming this ...zone can affect the ICD arrhythmia redetection or confirmation criteria. We report two cases of inappropriate ICD shocks due to the programming of a slow VT monitoring zone in the same device model.
BACKGROUND—Ventricular tachycardia (VT) substrate ablation usually requires extensive ablation. Scar dechanneling technique may limit the extent of ablation needed.
METHODS AND RESULTS—The study ...included 101 consecutive patients with left ventricular scar–related VT (75 ischemic patients; left ventricular ejection fraction, 36±13%). Procedural end point was the elimination of all identified conducting channels (CCs) by ablation at the CC entrance followed by abolition of residual inducible VTs. By itself, scar dechanneling rendered noninducibility in 54.5% of patients; ablation of residual inducible VT increased noninducibility to 78.2%. Patients needing only scar dechanneling had a shorter procedure (213±64 versus 244±71 minutes; P=0.027), fewer radiofrequency applications (19±11% versus 27±18%; P=0.01), and external cardioversion/defibrillation shocks (20% versus 65.2%; P<0.001). At 2 years, patients needing scar dechanneling alone had better event-free survival (80% versus 62%) and lower mortality (5% versus 11%). Incomplete CC-electrogram elimination was the only independent predictor (hazard ratio, 2.54 1.06–6.10) for the primary end point. Higher end point-free survival rates were observed in patients noninducible after scar dechanneling (log-rank P=0.013) and those with complete CC-electrogram elimination (log-rank P=0.013). The complications rate was 6.9%, with no deaths.
CONCLUSIONS—Scar dechanneling alone results in low recurrence and mortality rates in more than half of patients despite the limited ablation extent required. Residual inducible VT ablation improves acute results, but patients who require it have worse outcomes. Recurrences are mainly related to incomplete CC-electrogram elimination.
The aim of this study was to analyze whether scar characterization could improve the risk stratification for life-threatening ventricular arrhythmias and sudden cardiac death (SCD).
Among patients ...with a cardiac resynchronization therapy (CRT) indication, appropriate defibrillator (CRT-D) therapy rates are low.
Primary prevention patients with a class I indication for CRT were prospectively enrolled and assigned to CRT-D or CRT pacemaker according to physician's criteria. Pre-procedure contrast-enhanced cardiac magnetic resonance was obtained and analyzed to identify scar presence or absence, quantify the amount of core and border zone (BZ), and depict BZ distribution. The presence, mass, and characteristics of BZ channels in the scar were recorded. The primary endpoint was appropriate defibrillator therapy or SCD.
217 patients (39.6% ischemic) were included. During a median follow-up of 35.5 months (12 to 62 months), the primary endpoint occurred in 25 patients (11.5%) and did not occur in patients without myocardial scar. Among patients with scar (n = 125, 57.6%), those with implantable cardioverter-defibrillator (ICD) therapies or SCD exhibited greater scar mass (38.7 ± 34.2 g vs. 17.9 ± 17.2 g; p < 0.001), scar heterogeneity (BZ mass/scar mass ratio) (49.5 ± 13.0 vs. 40.1 ± 21.7; p = 0.044), and BZ channel mass (3.6 ± 3.0 g vs. 1.8 ± 3.4 g; p = 0.018). BZ mass (hazard ratio: 1.06 95% confidence interval: 1.04 to 1.08; p < 0.001) and BZ channel mass (hazard ratio: 1.21 95% confidence interval: 1.10 to 1.32; p < 0.001) were the strongest predictors of the primary endpoint. An algorithm based on scar mass and the absence of BZ channels identified 148 patients (68.2%) without ICD therapy/SCD during follow-up with a 100% negative predictive value.
The presence, extension, heterogeneity, and qualitative distribution of BZ tissue of myocardial scar independently predict appropriate ICD therapies and SCD in CRT patients.
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