Efficacy and Safety of Appropriate Shocks and Antitachycardia Pacing in Transvenous and Subcutaneous Implantable Defibrillators: Analysis of All Appropriate Therapy in the PRAETORIAN Trial.

BACKGROUND: The PRAETORIAN trial (A Prospective, Randomized Comparison of Subcutaneous and Transvenous Implantable Cardioverter Defibrillator Therapy) showed noninferiority of subcutaneous implantable cardioverter defibrillator (S-ICD) compared with transvenous implantable cardioverter defibrillator (TV-ICD) with regard to inappropriate shocks and complications. In contrast to TV-ICD, S-ICD cannot provide antitachycardia pacing for monomorphic ventricular tachycardia. This prespecified secondary analysis evaluates appropriate therapy and whether antitachycardia pacing reduces the number of appropriate shocks. METHODS: The PRAETORIAN trial was an international, investigator-initiated randomized trial that included patients with an indication for implantable cardioverter defibrillator (ICD) therapy. Patients with previous ventricular tachycardia <170 bpm or refractory recurrent monomorphic ventricular tachycardia were excluded. In 39 centers, 849 patients were randomized to receive an S-ICD (n=426) or TV-ICD (n=423) and were followed for a median of 49.1 months. ICD programming was mandated by protocol. Appropriate ICD therapy was defined as therapy for ventricular arrhythmias. Arrhythmias were classified as discrete episodes and storm episodes (≥3 episodes within 24 hours). Analyses were performed in the modified intention-to-treat population. RESULTS: In the S-ICD group, 86 of 426 patients received appropriate therapy, versus 78 of 423 patients in the TV-ICD group, during a median follow-up of 52 months (48-month Kaplan-Meier estimates 19.4% and 17.5%; P=0.45). In the S-ICD group, 83 patients received at least 1 shock, versus 57 patients in the TV-ICD group (48-month Kaplan-Meier estimates 19.2% and 11.5%; P=0.02). Patients in the S-ICD group had a total of 254 shocks, compared with 228 shocks in the TV-ICD group (P=0.68). First shock efficacy was 93.8% in the S-ICD group and 91.6% in the TV-ICD group (P=0.40). The first antitachycardia pacing attempt successfully terminated 46% of all monomorphic ventricular tachycardias, but accelerated the arrhythmia in 9.4%. Ten patients with S-ICD experienced 13 electrical storms, versus 18 patients with TV-ICD with 19 electrical storms. Patients with appropriate therapy had an almost 2-fold increased relative risk of electrical storms in the TV-ICD group compared with the S-ICD group (P=0.05). CONCLUSIONS: In this trial, no difference was observed in shock efficacy of S-ICD compared with TV-ICD. Although patients in the S-ICD group were more likely to receive an ICD shock, the total number of appropriate shocks was not different between the 2 groups. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01296022.

Device-related complications in subcutaneous versus transvenous ICD: a secondary analysis of the PRAETORIAN trial.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (S-ICD) is developed to overcome lead-related complications and systemic infections, inherent to transvenous ICD (TV-ICD) therapy. The PRAETORIAN trial demonstrated that the S-ICD is non-inferior to the TV-ICD with regard to the combined primary endpoint of inappropriate shocks and complications. This prespecified secondary analysis evaluates all complications in the PRAETORIAN trial. METHODS AND RESULTS: The PRAETORIAN trial is an international, multicentre, randomized trial in which 849 patients with an indication for ICD therapy were randomized to receive an S- ICD (N = 426) or TV-ICD (N = 423) and followed for a median of 49 months. Endpoints were device-related complications, lead-related complications, systemic infections, and the need for invasive interventions. Thirty-six device-related complications occurred in 31 patients in the S-ICD group of which bleedings were the most frequent. In the TV-ICD group, 49 complications occurred in 44 patients of which lead dysfunction was most frequent (HR: 0.69; P = 0.11). In both groups, half of all complications were within 30 days after implantation. Lead-related complications and systemic infections occurred significantly less in the S-ICD group compared with the TV-ICD group (P < 0.001, P = 0.03, respectively). Significantly more complications required invasive interventions in the TV-ICD group compared with the S-ICD group (8.3% vs. 4.3%, HR: 0.59; P = 0.047). CONCLUSION: This secondary analysis shows that lead-related complications and systemic infections are more prevalent in the TV-ICD group compared with the S-ICD group. In addition, complications in the TV-ICD group were more severe as they required significantly more invasive interventions. This data contributes to shared decision-making in clinical practice.

Oesophageal safety in voltage-guided atrial fibrillation ablation using ablation index or contact force only: a prospective comparison.

AIMS: Left atrial ablation using radiofrequency (RF) is associated with endoscopically detected thermal oesophageal lesions (EDELs). The aim of this study was to compare EDEL occurrence after conventional contact force-guided (CFG) RF ablation vs. an ablation index-guided (AIG) approach in clinical routine of voltage-guided ablation (VGA). Predictors of EDEL were also assessed. METHODS AND RESULTS: This study compared CFG (n = 100) with AIG (n = 100) in consecutive atrial fibrillation ablation procedures, in which both pulmonary vein isolation and VGA were performed. In the AIG group, AI targets were ≥500 anteriorly and ≥350-400 posteriorly. Upper endoscopy was performed after ablation.The CFG and AIG groups had comparable baseline characteristics. The EDEL occurred in 6 and 5% (P = 0.86) in the CFG and AIG groups, respectively. Category 2 lesions occurred in 4 and 2% (P = 0.68), respectively. All EDEL healed under proton pump inhibitor therapy. The AI > 520 was the only predictor of EDEL [odds ratio (OR) 3.84; P = 0.039]. The more extensive Category 2 lesions were predicted by: AI max > 520 during posterior ablation (OR 7.05; P = 0.042), application of posterior or roof lines (OR 5.19; P = 0.039), existence of cardiomyopathy (OR 4.93; P = 0.047), and CHA2DS2-VASc score (OR 1.71; P = 0.044). The only Category 2 lesion with AI max < 520 (467) occurred in a patient with low body mass index. CONCLUSIONS: Both methods were comparable with respect to clinical complications and EDEL. In consideration of previous reconnection data and our study results regarding oesophageal safety, optimal AI target range might be between 400 and 450.

Percutaneous balloon pericardiotomy: efficacy in a series of malignant and nonmalignant cases.

OBJECTIVE: In the case of malignant pericardial effusion and cardiac tamponade, balloon pericardiotomy is an established minimally invasive option to the surgical creation of a subxiphoid pericardial window. Percutaneous balloon pericardiotomy effectively drains recurrent pericardial fluid by creating a pleuro (-abdominal-) pericardial communication. Design. A series of 26 patients with underlying malignant (n = 12) and nonmalignant (n = 14) diseases underwent percutaneous balloon pericardiotomy between 2008 and 2021. All interventions were done through a subxiphoid access under local anesthesia. Results. The mean survival in the malignant and nonmalignant groups was 1.2 versus 48.0 months, respectively (p < .001). There were neither severe periinterventional complications nor in-hospital deaths. In two patients with nonmalignant disease the surgical creation of a pericardial window was necessary during follow-up. The originally described procedure was modified by the removal of all catheters at the end of the intervention. The procedure was safe. It prevented immobility and facilitated an early discharge from the hospital. Conclusion. Our experiences show that percutaneous balloon pericardiotomy is a minimally invasive approach to successfully provide palliation in the group of patients with underlying malignant disease. On the other hand, we have shown that this technique is safe and feasible in the treatment of pericardial effusion based on nonmalignant disease. We think thereby that pericardial balloon pericardiotomy can be considered as a less invasive alternative to surgery in both groups of patients.

Predictors of future arrhythmic events in patients with unexplained syncope.

AIMS: The purpose of this study was to examine the usefulness of implantable loop recorders (ILRs) for symptom-rhythm correlation and to identify predictors of future arrhythmic events. PATIENTS AND METHODS: In our dual-centre study, we analysed ILR data of 189 patients (mean age 67.4 ± 15.2 years, 114 male) with unexplained syncope (single syncope 21 patients, recurrent 168 patients, traumatic injury 43 patients). Patients had severe comorbidities such as hypertension (n = 127), coronary artery disease (n = 31), diabetes mellitus (n = 33) and chronic renal insufficiency (n = 18). The median ILR usage was 29 months (M), with a range between 1 and 46 M. RESULTS: Forty-nine (26%) patients experienced syncope during the study, with a median of 8 M to first recurrence of syncope. In 43 patients, pacemaker implantation was performed because of sinus node disease (n = 29), high-degree AV-block (n = 6) or atrial fibrillation with slow ventricular rate (n = 8). In five patients, an ICD was implanted because of documented ventricular tachycardia (n = 4) or left ventricular ejection fraction <35% (n = 1). One patient received ablation of the cavotricuspid isthmus because of documented atrial flutter. Concerning the clinical course, in five patients explantation of the ILR was necessary due to pocket infection. Three patients died due to non-cardiac causes. Logistic regression analysis revealed that older patients had a significantly higher risk for future arrhythmic events (OR 1.3, p = .039). CONCLUSIONS: ILR monitoring is effective in indicating causes of unexplained syncope by providing symptom-rhythm associations. Only age was a predictor of future arrhythmic events. The mortality in patients with unexplained syncope was very low.

Optimization of the atrioventricular delay during cardiac resynchronization therapy using a device for non-invasive measurement of cardiac index at rest and during exercise.

AIMS: It is not clear whether cardiac resynchronization therapy (CRT) should only be optimized at rest or whether it is necessary to perform CRT optimization during exercise. Our study aims to answer this question by using an inert gas rebreathing method (Innocor®). METHODS AND RESULTS: Twenty-seven patients with congestive heart failure and implanted CRT devices were included in the study. The aetiology of the heart failure was ischaemic in nine (33%) patients. Patients had low left ventricular ejection fraction (29 ± 8%) and enlarged LV end-diastolic diameters (63 ± 7 mm). Atrioventricular delay (AVD) was optimized at rest according to cardiac index (CI), measured by inert gas rebreathing (Innocor®). Thereafter, patients performed standardized, steady-state bicycle exercise at 30 W in sitting body position. Three AVDs were tested during exercise in a random sequence: optimized resting AVD (AVD(opt)) according to baseline measurement; AVD(opt) - 30 ms; and AVD(opt) + 30 ms. Cardiac index was measured in each AVD by inert gas rebreathing. Cardiac index increased significantly during exercise. However, neither AVD(opt) shortening nor prolongation during exercise had significant effect on CI (shortening of AVD(opt) - 30 ms was accompanied by a reduction of CI of 4.8%, prolongation of AVD(opt) + 30 ms was accompanied by a reduction of CI of 7.7%). CONCLUSION: Shortening or lengthening of the AVD during exercise has no impact on CI in CRT patients. On the basis of our results, we conclude that in CRT patients the AVD should be programmed, fixed even during exercise.

Cardiac magnetic resonance imaging as a tool to link cardiac conduction disease to myocarditis with minimal left ventricular impairment.

Myocarditis is an injury of the myocardium caused by a variety of agents. Conduction disturbances such as complete atrioventricular block (AV block) may occur as an infrequent but serious complication of myocarditis. Early detection and accurate diagnosis of myocarditis are still unresolved challenges. We present 2 cases of otherwise mild myocarditis complicated by high-degree AV block in combination with isolated delayed uptake of contrast at the septal regions in the cardiac magnetic resonance imaging. Because the AV block was persistent in both cases, permanent pacemaker implantation was necessary. Delayed enhancement in the septal area in myocarditis might be predictive of infra-Hisian AV block.

Multidimensional ECG-based analysis of cardiac autonomic regulation predicts early AF recurrence after electrical cardioversion.

BACKGROUND: Heart rate turbulence, deceleration capacity (DC), and symbolic dynamics (SD) are promising novel domains of autonomic indices representing the multidimensional qualities of autonomic heart rate dynamics. PURPOSE: The aim of this study was to test the impact of these novel indices in predicting early AF recurrence within the first month after electrical cardioversion (CV). METHODS: In 45 patients with AF, standard Holter recordings were commenced immediately after CV. Holter-based indices were retrospectively analyzed using computerized algorithms. The best indices were applied in a multivariate model to select the optimal combination set that correctly classified patients who developed early AF recurrence. RESULTS: Early AF recurrence occurred in 25 vs 20 patients with stable sinus rhythm. The set with the highest predictive power consisted of DC, turbulence onset, VLF/P, and PTH19 as a parameter of SD. The receiver operating curve analysis applied to this optimum set produced an area under the curve of 0.86, thus correctly classifying patients with 95.0% specificity and 76.0% sensitivity. CONCLUSION: The analysis of novel multidimensional Holter-based autonomic indices after CV appears of clinical value because the procedure identifies patients with high risk of early AF recurrence. Furthermore, it indicates a substantial alteration of autonomic regulation.

Ordinary AV Nodal Reentry Tachycardia-Unusual Ablation: A Case Report and Review of the Literature.

A 72-year-old woman was referred to us with typical symptoms of paroxysmal supraventricular tachycardia for electrophysiological diagnostics and catheter ablation. During the first session of catheter ablation, a probing of the right ventricle was not successful. Therefore, an angiography of the central veins was performed. A rare anatomical variation with atresia of the inferior vena cava below the hepatic veins with azygos persistence was detected. The blood of the lower half of the body was drained via the dilated azygos into the superior vena cava; the blood of the liver veins enters into the right atrium directly. By atypical catheter placement over the azygos vein in the right ventricle and coronary sinus, an AV nodal reentry tachycardia (AVNRT) could be confirmed as the mechanism of tachycardia. However, a stable position of the ablation catheter could not be achieved by the femoral approach, so the successful AV node modulation with ablation of the slow pathway was performed via jugular access.

QRS duration and QTc interval are predictors of risk for ventricular arrhythmias during cardiac resynchronization therapy.

BACKGROUND AND OBJECTIVES: QRS duration (QRSd) and prolonged corrected QT interval (QTc) are associated with ventricular arrhythmic events. This study was designed to determine whether CRT by means of biventricular pacing alters the QTc and QRSd, and whether such changes are related to the risk of sustained ventricular tachyarrhythmias (sVTA). METHODS AND RESULTS: A total of 127 patients (102 men, mean age 63.9 +/- 8.9 years) with drug-resistant heart failure and QRS duration > or = 130 ms underwent CRT/CRT-ICD. The aetiology of the heart failure was ischaemic in 41 patients (32.3%). After a median follow-up of 24 months, 42 sVTA occurred in 35 patients (27.6%). Twenty-nine patients had a single sVTA, in five patients two sVTA and in one patient three sVTA occurred. The paced QTc was longer in sVTA patients (505 +/- 55 ms) compared with no sVTA patients (486 +/- 44 ms, P < or = 0.003). Similar responses for paced QRSd were observed (182 +/- 27 ms in sVTA patients vs 167 +/- 27 ms in no-sVTA patients, P < or = 0.03). This effect was independent from intrinsic QTc and QRSd and the aetiology of the heart failure. The mortality rate was significantly higher in patients with ventricular fibrillation and fast VT (P < or = 0.004) who experienced shock therapies. However, the sVTA were not the immediate cause of death. CONCLUSIONS: A pacing-induced increase in QTc and QRSd is related to sVTA in patients with CRT. Further studies are needed to determine whether optimization of CRT with the goal to achieve a narrow paced QRSd can reduce the occurrence of sVTA.

Voltage-guided ablation in persistent atrial fibrillation-favorable 1-year outcome and predictors.

INTRODUCTION: Pulmonary vein isolation (PVI) in persistent atrial fibrillation (AF) has a low success rate. A newer ablation concept targets left atrial (LA) low voltage zones (LVZ) which correlate with fibrosis and predict recurrence after PVI. We aimed to determine the success of combined PVI- and LVZ-guided ablation and to identify the predictors for LVZ and for ablation success. METHODS AND RESULTS: A total of 119 consecutive patients who underwent their first ablation procedure due to persistent AF were included. After acquisition of a high-resolution LA voltage map, PVI- and LVZ-guided ablation were performed. Mean age was 69 ± 8 years, 53% were men, and 8% had longstanding persistent AF. We found LVZ in 55% of patients. Twelve-month freedom from recurrences off drugs was 69%. The only independent predictor for recurrence was the existence of LVZ (OR 4.2, 95% CI 1.54-11.41, p = 0.005). Existence of LVZ was predicted positively by age ≥ 67 years (OR 4.4, 95% CI 1.4-13.7, p = 0.011), LA volume index ≥ 68 ml/m2 (OR 3.9, 95% CI 1.4-10.5, p = 0.008), and GFR ≤ 85 ml/min/1.73 m2 (OR 12.5, 95% CI 2.0-76.6, p = 0.006). BMI ≥ 26 kg/m2 (OR 0.06, 95% CI 0.01-0.30, p = 0.001) was a negative predictor of LVZ. CONCLUSION: LVZ-guided ablation in combination with PVI results in comparably high success rates. However, the existence of LVZ remains the strongest predictor of ablation success.

Pulmonary vein isolation using second-generation single-shot devices: not all the same?

INTRODUCTION: Single-shot devices have been developed to simplify pulmonary vein isolation (PVI). Randomized studies of the second-generation cryoballoon (CB 2nd) demonstrated excellent results. There are limited data comparing results of circular pulmonary vein ablation catheter (PVAC) with conventional RF ablation or CB for PVI. OBJECTIVE: Using a sequential registry cohort and a prospective randomized study, we aimed to compare the acute and long-term results of CB 2nd and PVAC Gold. METHODS: In the registry, consecutive patients with paroxysmal atrial fibrillation (AF) undergoing their first PVI were included. The preferred method used was PVAC Gold in 2014 and CB 2nd in 2015. Subsequently, a randomized study (PVAC vs. CB 2nd) was performed. Ablation success was measured as freedom of AF or atrial tachycardias (AT) off antiarrhythmic drugs. RESULTS: In the registry cohort, PVAC Gold was used in 60 patients and CB 2nd in 56 patients (age 66 ± 11 years, 52% male, LAD 43 ± 6). In the randomized study, 20 patients were treated with PVAC Gold and 22 with CB 2nd (age 67 ± 9; 43% men, LAD 40 ± 7 mm). During a mean follow up of 13.2 ± 3.6 months, success was 54% in PVAC Gold patients and 81% in CB 2nd cases (p = 0.001). In the randomized study 12 months success was 50% versus 86%, p < 0.05. Complications occurred rare in both groups. CONCLUSIONS: Our registry data and the randomized study both suggest superiority of PVI using CB 2nd as compared with PVI using PVAC Gold.

SCN5A channelopathies--an update on mutations and mechanisms.

Voltage-gated Na+ channels mediate the rapid upstroke of the action potential in excitable tissues. Na(v)1.5, encoded by the SCN5A gene, is the predominant isoform in the heart. Mutations in SCN5A are associated with distinct cardiac excitation disorders often resulting in life-threatening arrhythmias. This review outlines the currently known SCN5A mutations linked to three distinct cardiac rhythm disorders: long QT syndrome subtype 3 (LQT3), Brugada syndrome (BS), and cardiac conduction disease (CCD). Electrophysiological properties of the mutant channels are summarized and discussed in terms of Na+ channel structure-function relationships and regarding molecular mechanisms underlying the respective cardiac dysfunction. Possible reasons for less convincing genotype-phenotype correlations are suggested.

Combination of cardiac conduction disease and long QT syndrome caused by mutation T1620K in the cardiac sodium channel.

AIMS: The aim of the present study was to elucidate the molecular mechanism underlying the concomitant occurrence of cardiac conduction disease and long QT syndrome (LQT3), two SCN5A channelopathies that are explained by loss-of-function and gain-of-function, respectively, in the cardiac Na+ channel. METHODS AND RESULTS: A Caucasian family with prolonged QT interval, intermittent bundle-branch block, sudden cardiac death, and syncope was investigated. Lidocaine (1 mg/kg i.v.) normalized the prolonged QT interval and rescued bundle-branch block. An SCN5A mutation analysis was performed that revealed a C-to-A mutation at position 4859 (exon 28), predicted to change a highly conserved threonine for a lysine at position 1620. Mutant channels were characterized both in Xenopus oocytes and HEK293 cells. The T1620K mutation remarkably altered the properties of Nav1.5 channels. In particular, the voltage-dependence of the current decay time constants was largely lost. As a consequence, mutant channels inactivated faster than wild-type channels at potentials negative to -30 mV, resulting in less Na+ inward current (loss-of-function), but significantly slower at potentials positive to -30 mV, resulting in an increased Na+ inward current (gain-of-function). Moreover, we found a hyperpolarized shift of steady-state activation and an accelerated recovery from inactivation (gain-of-function). At the same time, channel availability was significantly reduced at the resting membrane potential (loss-of-function). CONCLUSION: We conclude that lysine at position 1620 leads to both loss-of-function and gain-of-function properties in hNav1.5 channels, which may consequently cause in the same individuals impaired impulse propagation in the conduction system and prolonged QTc intervals, respectively.

Very Low Frequency Heart Rate Variability Predicts the Development of Post-Stroke Infections.

Stroke-induced immunodepression is a major risk factor for severe infectious complications in the immediate post-stroke period. We investigated the predictive value of heart rate variability (HRV) to identify patients at risk of post-stroke infection, systemic inflammatory response syndrome, or severe sepsis during the post-acute interval from days 3 to 5 after stroke onset. A prospective, observational monocentric cohort study was conducted in a university hospital stroke unit of patients with ischemic infarction in the territory of the middle cerebral artery without an ongoing infection at admission. Standard HRV indices were processed from Holter ECG. Recording started within the first day after the onset of stroke. Infection (primary endpoint: pneumonia, urinary tract, unknown localization) was assessed between days 3 and 5. The predictive value of HRV adjusted for clinical data was analyzed by logistic regression models and area under the receiver operating characteristic curve (AUC). From 287 eligible patients, data of 89 patients without event before completion of 24-h Holter ECG were appropriate for prediction of infection (34 events). HRV was significantly associated with incident infection even after adjusting for clinical covariates. Very low frequency (VLF) band power adjusted for both, the National Institutes of Health Stroke Scale (NIHSS) at admission and diabetes predicted infection with AUC = 0.80 (cross-validation AUC = 0.74). A model with clinical data (diabetes, NIHSS at admission, involvement of the insular cortex) performed similarly well (AUC = 0.78, cross-validation AUC = 0.71). Very low frequency HRV, an index of integrative autonomic-humoral control, predicts the development of infectious complications in the immediate post-stroke period. However, the additional predictive value of VLF band power over clinical risk factors such as stroke severity and insular involvement was marginal. The continuous HRV monitoring starting immediately after admission might probably increase the predictive performance of VLF band power. That needs to be clarified in further investigations.

Efficacy of temperature-guided cryoballoon ablation without using real-time recordings - 12-Month follow-up.

BACKGROUND: We sought to evaluate a temperature-guided approach of cryoballoon (CB) ablation without visualization of real-time recordings. METHODS AND RESULTS: We analysed 166 patients (34.9% female, 60 ±â€¯11 years) with paroxysmal or short-term persistent atrial fibrillation (AF). Comorbidities included diabetes mellitus (n = 28), coronary artery disease (n = 24), hypertension (n = 122), previous stroke or TIA > 3 months (n = 12). Cryoablation of the pulmonary veins (PV) was performed using first-generation (n = 78) and second-generation CB (n = 88). Two 5-minute freezes were performed for the first-generation and two 4-minute freezes for the second-generation CB with the intention to achieve a temperature drop below -40 °C. At 12-month follow-up, we observed overall freedom from AF in 92 patients (56.6%, mean time to AF recurrence 3.4 ±â€¯2.9 months). There was a significant difference in freedom from AF between first-generation CB (45%) and second-generation CB (67%; p < 0.005). Complications were groin hematoma (4.8%) and phrenic nerve palsy (PVP) (2.4%). PVP disappeared after 12 months in all patients. Three patients developed cardiac tamponade (1.8%) that resolved without further sequelae after pericardiocentesis. Multivariate analysis revealed that only the achieved temperature in the right inferior PV (RIPV) was a predictor of long-term freedom from AF (OR 0.9; p = 0.014). Female gender was a predictor of AF recurrence (OR 6.1; p = 0.022). CONCLUSION: Temperature-guided CB ablation without real-time recordings is feasible and safe without reducing the efficacy if second-generation CB is used. Deep nadir temperatures especially in the RIPV are necessary for long term-success.

Transesophageal left ventricular posterior wall potential in heart failure patients with biventricular pacing.

INTRODUCTION: Biventricular (BV) pacing is an established therapy for heart failure (HF) patients with intraventricular conduction delay, but not all patients improved clinically. We investigated the interventricular delay (IVD) by means of the transesophageal left ventricular posterior wall potential (LVPWP). MATERIALS AND METHODS, AND RESULTS: A total of 18 HF patients (age 62+/-9 years; 15 males) with NYHA class 3.1+/-0.3, LV ejection fraction 22+/-7%, left bundle branch block and a QRS duration (QRSD) of 171+/-27 ms were analyzed using transesophageal LVPWP before implantation of a BV pacing device. The median follow up was 14+/-14 months. In 14 responders, IVD was 81+/-25 ms with a QRSD/IVD ratio of 2.2+/-0.3 with reclassification of NYHA class 3.1+/-0.3 to 2.0+/-0.5 (p<0.001) and an increase in LV ejection fraction from 22+/-7% to 36+/-11% (p=0.001) during long-term BV pacing. In four non-responders, transesophageal IVD was significantly smaller at 30+/-11 ms (p=0.001). CONCLUSION: Transesophageal IVD may be a useful method to detect responders to BV pacing. Transesophageal LVPWP may be a simple and useful technique to detect clinical responders to BV pacing in HF patients.

Termination of atrial flutter by directed transesophageal atrial pacing during transesophageal echocardiography.

INTRODUCTION: The purpose of this study was to evaluate termination of atrial flutter (AFL) by directed rapid transesophageal atrial pacing (TAP) with and without simultaneous transesophageal echocardiography (TEE) performed using a novel TEE tube electrode. MATERIALS AND METHODS, AND RESULTS: A total of 16 AFL patients (age 63+/-12 years; 13 males) with mean AFL cycle length of 224+/-24 ms (n=12) and mean ventricular cycle length of 448+/-47 ms (n=12) were analyzed using either an esophageal TO electrode (n=10) or a novel TEE tube electrode consisting of a tube with four hemispherical electrodes that is pulled over the echo probe (n=6). AFL could be terminated by directed rapid TAP using an esophageal TO electrode, leading to induction of atrial fibrillation (AF) (n=6), induction of AF and spontaneous conversion to sinus rhythm (SR) (n=3), and with conversion to SR (n=1). AFL could also be terminated by directed rapid TAP using the TEE tube electrode, with induction of AF (n=3) or induction of AF and spontaneous conversion to SR (n=3). CONCLUSION: AFL can be terminated by directed rapid TAP with hemispherical electrodes with and without simultaneous TEE. TAP with the directed TEE tube electrode is a safe, simple, and useful method for terminating AFL.

[Acute chest pain and new ECG changes in pacemaker patients : A clinical challenge]. / Akuter Thoraxschmerz in Verbindung mit neuen EKG-Veränderungen bei Schrittmacherpatienten : Eine klinische Herausforderung.

We report the case of a 82-year-old woman who was admitted to our institution with acute chest pain, nausea, and vomiting. Because of atrial fibrillation with intermittent bradycardia, a single-chamber pacemaker was implanted 4 years ago. The initial 12-lead ECG showed atrial fibrillation with a heart rate of 70 bpm, narrow QRS, and T­wave inversions in the inferolateral leads. Coronary artery disease was excluded by immediate cardiac catheterization. A subsequent ECG three hours later showed a ventricular paced rhythm. During the subsequent clinical course, cardiac injury markers remained normal. However, serum amylase and lipase levels were 5 times above the normal range. According to these clinical findings, acute pancreatitis was the most likely diagnosis. Abdominal ultrasound excluded pancreatic necrosis and gallstones. Initial treatment consists of fasting, pain control, and intravenous fluids with resolution of symptoms after a few days. The patient could be discharged 7 days later. In conclusion, the observed ECG findings in combination with chest pain are suggestive for myocardial ischemia mandating immediate cardiac catheterization. However, acute pancreatitis might present with the aforementioned ECG changes and symptoms. The case was further complicated by a distinct electrocardiographic memory effect due to intermittent ventricular pacing.

ST-segment Elevation Following Cardioversion of Atrial Fibrillation in the Emergency Department: Unmasked Myocardial Infarction due to Left Main Coronary Artery Plaque Rupture or Unspecific Finding?

Atrial fibrillation (AF) is a frequent reason for emergency department visits. According to current guidelines either rate- or rhythm-control are acceptable therapeutic options in such situations. In this report, we present the complicated clinical course of a patient with AF and a rapid ventricular response. Because of paroxysmal AF, the patient was on chronic oral anticoagulation therapy with warfarin. Pharmacological treatment was ineffective to control ventricular rate, and immediate synchronized electrical cardioversion was performed. One hour later, the patient complained of chest pain in combination with marked ST-segment elevation in the anterior leads. Cardiac catheterization with optical coherence tomography disclosed plaque rupture in the left main coronary artery without other significant stenosis. Stent implantation was performed successfully. During the course of the hospital stay, the patient remained asymptomatic and the ST-segment elevations resolved. However, despite treatment with amiodarone it was not possible to keep the patient permanently in sinus rhythm. Therefore, a biventricular pacemaker was implanted and AV node ablation performed.