Asymmetrical left atrial remodelling in atrial fibrillation: relation with diastolic dysfunction and long-term ablation outcomes.

AIMS: The association between anatomical left atrial (LA) remodelling and ventricular diastolic dysfunction (DD) in atrial fibrillation (AF) patients is not well studied. We aimed to examine the effect of DD on anatomic LA remodelling and their relation with ablation outcomes. METHODS AND RESULTS: In 104 patients (58 ± 10 years, 69% male) referred for AF ablation, LA volume (LAV) was determined by computed tomography. A cutting plane, between the pulmonary vein (PV) ostia and the appendage and parallel to the posterior wall, divided LAV into anterior- (LA-A) and posterior-LA parts. The ratio of LA-A and LAV was defined as the LA asymmetry index (ASI). According to the current guidelines, the presence of DD was evaluated by echocardiography. Regression analysis was used to identify predictors of asymmetry changes and long-term success. Univariate linear regression revealed that ASI is associated with LAV, the presence of DD, and mitral regurgitation. Asymmetry index was higher in patients with DD (n = 35, 62 ± 5 vs. 59 ± 6%, P = 0.013) or mitral regurgitation (n = 67, 61 ± 6 vs. 58 ± 5%, P = 0.025). Multiple linear regression analysis showed that DD (B = 2.6, ß = 0.207, 95% confidence interval, CI: 0.167-5.011, P = 0.036) and LAV (B = 0.037, ß = 0.211, 95% CI: 0.003-0.071, P = 0.033) were the only factors independently associated with ASI (adjusted r2 = 0.92, F = 6.2, P = 0.003). Regression analysis showed that AF recurrence (33% after 24 months) is associated with asymmetric LA changes, while DD is not. CONCLUSIONS: Left atrial symmetry changes are associated with DD and dilatation. Since DD could cause LA remodelling, appropriate early treatment should be considered for AF patients with DD, before geometrical changes occur.

[How to do a stress echocardiography?]. / Stress-Echokardiografie.

Stress echocardiography (SE) is a powerful functional imaging technique to assess cardiac performance under work conditions. The main indication is the detection of myocardial ischemia due to coronary artery disease (CAD), however it can also be used in patients with structural heart disease (e. g. valvular disease, hypertrophic obstructive cardiomyopathy). Dynamic or pharmacological (dobutamine / adenosine) modalities are available to induce cardiac stress, basically depending on the clinical problem and the patient's ability to exercise. Exercise on a treadmill or a semi-supine bicycle is the most physiological way to induce stress. Dobutamine stimulation is useful in patients who are unable to exercise and for detection of viable myocardium in hypo- or akinetic segments. Adenosin-induced hyperaemia causes steal effects in myocardial segments with significant CAD. Main limitations of SE are the need for an appropriate acoustic window and the user-dependent variability with regard to the interpretation of the results.

Results of catheter ablation of atrial fibrillation in hypertrophied hearts - Comparison between primary and secondary hypertrophy.

BACKGROUND AND PURPOSE: Approximately 20-25% of the patients with hypertrophic cardiomyopathy (HCM) develop atrial fibrillation (AF) during the clinical course of the disease, a percentage significantly larger than that of the general population. The purpose of the present study was to report on the procedural results of patients with AF and either primary or secondary left ventricular hypertrophy (LVH). METHODS AND SUBJECTS: Twenty-two consecutive HCM patients (55% male, mean age 57±8 years) with symptomatic AF, having undergone AF ablation procedures between September 2009 and July 2012 were compared with respect to procedural outcome and follow-up characteristics with 22 matched controls with secondary cardiac hypertrophy (64% male, 63±10 years) from our prospective AF catheter ablation registry. RESULTS AND CONCLUSION: Radiofrequency catheter ablation (RFCA) was successful in restoring long-term sinus rhythm in patients with LVH due to HCM and due to secondary etiology. However, patients with HCM needed more RFCA procedures and frequently additional antiarrhythmic drug therapy in order to maintain sinus rhythm.

Left bundle branch block, an old-new entity.

Left bundle branch block (LBBB) is generally associated with a poorer prognosis in comparison to normal intraventricular conduction, but also in comparison to right bundle branch block which is generally considered to be benign in the absence of an underlying cardiac disorder like congenital heart disease. LBBB may be the first manifestation of a more diffuse myocardial disease. The typical surface ECG feature of LBBB is a prolongation of QRS above 0.11 s in combination with a delay of the intrinsic deflection in leads V5 and V6 of more than 60 ms and no septal q waves in leads I, V5, and V6 due to the abnormal septal activation from right to left. LBBB may induce abnormalities in left ventricular performance due to abnormal asynchronous contraction patterns which can be compensated by biventricular pacing (resynchronization therapy). Asynchronous electrical activation of the ventricles causes regional differences in workload which may lead to asymmetric hypertrophy and left ventricular dilatation, especially due to increased wall mass in late-activated regions, which may aggravate preexisting left ventricular pumping performance or even induce it. Of special interest are patients with LBBB and normal left ventricular dimensions and normal ejection fraction at rest but who may present with an abnormal increase in pulmonary artery pressure during exercise, production of lactate during high-rate pacing, signs of ischemia on myocardial scintigrams (but no coronary artery narrowing), and abnormal ultrastructural findings on myocardial biopsy. For this entity, the term latent cardiomyopathy had been suggested previously.

Predictors of treatment in acute coronary syndromes in the elderly: impact on decision making and clinical outcome after interventional versus conservative treatment.

BACKGROUND: Management of elderly patients with acute coronary syndromes (ACS) is not standardized and physicians discretion for invasive versus conservative strategies lacks sufficient evidence. The purpose of this analysis was, therefore, to evaluate treatment strategies and outcomes of elderly patients with ACS and to highlight reasons for the treatment decision in a consecutive series of elderly patients. METHODS: This is a retrospective analysis of 1,001 elderly patients (>75 years) presenting with ACS. Patients were identified on the basis of their final discharge diagnosis. Baseline data, past medical history, cardiac and noncardiac concomitant diseases, treatment strategy, and adverse outcomes were evaluated, using patient's charts. Various co-variates were used to determine the association or predictive value of these co-variates to the invasive versus conservative management of the subjects. Thirty-day mortality and long-term survival were assessed either directly or in discharged patients via telephone interview with the patients, the patients' relatives or the primary care physicians. RESULTS: A total of 776 (77.5%) patients were treated invasively and 225 (22.5%) conservatively. Logistic regression analysis revealed that patients with advanced age, Killip class > II, pre-existing coronary artery disease, prior stroke, pre-existing renal failure, obesity, non-ST-elevation myocardial infarction, prior ACS, and the presence of supraventricular arrhythmias were significantly more likely to undergo conservative treatment. In-hospital mortality was significantly higher in conservatively treated patients (P < 0.001). CONCLUSION: In this retrospective analysis, we identified age as the main predictor for a conservative treatment strategy in elderly patients, albeit an invasive strategy was associated with a significantly better outcome.

Cardio-respiratory exercise testing early after the use of the Angio-Seal system for arterial puncture site closure after coronary angioplasty.

AIMS: The vascular closure device (VCD) Angio-Seal is an easy-to-use system for the closure of arterial puncture sites after percutaneous coronary intervention (PCI), and allows for early mobilisation of the patient. However, little data are available about exercising early after the use of VCD's in PCI patients. METHODS AND RESULTS: A total of 230 consecutive patients were screened. Of these, 45 (20%) were excluded due to the inability to perform exercise testing, or anatomical conditions which prevented the insertion of a VCD. The 185 remaining patients (139 male, mean age 68 ± 12 years) received Angio-Seal after PCI. After four hours, 30 patients (16%) showed a small local haematoma, 11 patients (6%) complained about minor -and one patient (0.5%) about strong- groin pain. There were no major bleeding complications, six pseudo-aneurysmata, and one arterio-venous fistula. Overall, nine patients (6%) showed moderate to severe groin problems. Patients without major complications underwent bicycle cardiopulmonary exercise testing the subsequent day. Exercise testing was performed up to 136 ± 60 W in 176 patients (94%). Maximum workload was 104 ± 33 W, peak oxygen consumption 17.6 ± 5.1 ml/min/kg, and oxygen consumption at the anaerobic threshold 15.4 ± 4.2 ml/min/kg. After exercise testing there were no cardiovascular complications noted. CONCLUSIONS: In patients receiving VCD after PCI, exercise testing above the anaerobic threshold was feasible after Angio-Seal deployment in those patients with no complications after the use of the device.

A new angiographic method to assess coronary flow reserve-validation in humans.

BACKGROUND: Coronary flow reserve (CFR) is defined as the ratio between coronary artery flow during maximal hyperemia and rest. It is considered as a marker for the integrity of the epicardial coronary circulation and the microcirculation. CFR measurement typically requires the introduction of a guide wire into a diseased coronary artery. We tested a new algorithm, which allows to estimate CFR by analysis of coronary angiograms without the need for direct intracoronary measurements. METHODS: Twenty seven patients (10 female, mean age 64 +/- 11 years) underwent diagnostic cardiac catheterization for the evaluation of chest pain. A Doppler wire was introduced into the diseased coronary artery and CFR(doppler) was calculated by the flow velocity ratio between rest and maximal hyperemia, induced by intravenous administration of 140 microg of adenosine per kg bodyweight. This was compared to the angiographically determined CFR (CFR(angio)) under the same conditions (rest and induced maximal hyperemia) by densitometry. CFR(angio) was based on the creation of two time density curves representing the disappearance of contrast over time. CFR(angio) was the resulting ratio between the density values during hyperemia and rest. RESULTS: An excellent correlation was found between CFR(doppler) and CFR(angio): CFR(angio) = 1 x CFR(doppler) (r = 0.87; P < 0.0001). The average absolute difference between both indeces was 0.36 +/- 0.31. CONCLUSION: Measurement of CFR(angio) by densitometry is feasible and provides results, which are comparable to Doppler-derived intracoronary flow velocity measurements.

Long-term effects of dynamic atrial overdrive pacing on sleep-related breathing disorders in pacemaker or cardioverter defibrillator recipients.

INTRODUCTION: Sleep-related breathing disorders occur in 20-30% of Europeans and North Americans, including 10% of sleep apnea syndrome (SAS). A preliminary study suggested that atrial overdrive pacing with a fixed heart rate might alleviate SAS. However, it is not known whether dynamic atrial overdrive pacing alleviates SAS. METHODS: Patients with indications for a dual chamber pacemaker or implantable cardioverter-defibrillator (ICD) were screened for SAS using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. If PSQI was >5, cardio-respiratory polygraphy was performed before and 4 and 7 months after device implantation. Patients were randomized to algorithm ON-OFF (group A) or OFF-ON (group B) and the apnea-hypopnea index (AHI) was measured. RESULTS: Out of 105 consecutive patients, 46 (44%) had a positive PSQI. This analysis included 12 patients (mean age = 61 +/- 10 years, body mass index 28.9 +/- 6.5 kg/m(2), left ventricular ejection fraction = 38.3 +/- 13.6%; 10 men). All patients suffered from obstructive or mixed SAS. There were no significant differences in PSQI or AHI between baseline and follow-up or between the two study groups. Therefore, the study was terminated ahead of schedule. CONCLUSIONS: The prevalence of obstructive or mixed SAS was high in pacemaker or ICD recipients and reduced left ventricular ejection fraction. In these patients, long-term dynamic atrial overdrive pacing using did not improve PSQI or SAS. Therefore, patients with relevant obstructive or mixed SAS should not be offered atrial pacing therapy.

Effect of cardiac resynchronization therapy on sleep quality, quality of life, and symptomatic depression in patients with chronic heart failure and Cheyne-Stokes respiration.

Patients with heart failure (HF) often suffer from sleep-related breathing disorders (SRBD) like Cheyne-Stokes respiration (CSR). Cardiac resynchronization therapy (CRT) improves myocardial function and exercise capacity in patients with HF and conduction disturbances. As CRT has been shown to reduce CSR in patients with HF, it is not clear whether CRT improves quality of life and symptomatic depression by improvement of apnea/hypopnea index (AHI) and sleep quality. Forty-two HF patients with conduction disturbance before CRT were screened for CSR and evaluated for sleep quality [Pittsburgh Sleep Quality Index (PSQI)], quality of life score [36-item short form (SF-36)], depression, and exercise capacity (VO2 peak) and ejection fraction (EF). Eighteen patients (three females, age 61+/-10, body mass index 24+/-4 kg m(-2), EF 24+/-4%, QRS complex duration 156+/-32 ms) presented CSR with an AHI of 18+/-8 (11 CSR, 7 mixed). Fourteen patients showed no SRBD (PSQI<5,AHI<5). All patients received CRT and were reevaluated after 18+/-7 weeks. CSR worsen quality of life in seven of eight terms compared to patients without SRBD. Symptomatic depressive symptoms (Beck Depression Inventory>10) were only present in patients with CSR. CRT results in improvement of peak VO2 and EF. There was no difference between patients with CSR and without SRBD on exercise capacity or EF under CRT, whereas CRT led to a significant decrease in AHI (18+/-8 to 3+/-2, p<0.0001), PSQI (18+/-4 to 6+/-3, p=0.0007), with reduction of depression score (12+/-3 to 4.8+/-3, p=0.004). In patients with HF, CSR is associated with symptomatic depressive syndromes and impaired quality of life. CRT reduced CSR with improvement of sleep quality and symptomatic depression.

Cardiac resynchronization therapy improves central sleep apnea and Cheyne-Stokes respiration in patients with chronic heart failure.

OBJECTIVES: We studied the effects of cardiac resynchronization therapy (CRT) on heart failure (HF) patients with central sleep apnea (CSA). BACKGROUND: Patients with advanced HF often suffer from CSA with Cheyne-Stokes respiration. Cardiac resynchronization therapy improves myocardial function and exercise capacity in HF patients with conduction disturbances. The relationship between CRT and CSA is currently unknown. METHODS: Twenty-four patients (7 females; 62 +/- 11 years) with HF, a reduced left ventricular ejection fraction (24 +/- 6%), and left bundle branch block (QRS duration 173 +/- 22 ms) received a CRT device. The number of apneas and hypopneas per hour (apnea-hypopnea index [AHI]) and minimal oxygen saturation (SaO2min) were quantified by cardiorespiratory polygraphy. Fourteen patients showed CSA (AHI >5/h), and 10 patients had an AHI <5/h without CSA. Subjective sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI). Data were evaluated before and after 17 +/- 7 weeks of CRT. RESULTS: In patients with CSA, CRT led to a significant decrease in AHI (19.2 +/- 10.3 to 4.6 +/- 4.4, p < 0.001) and PSQI (10.4 +/- 1.6 to 3.9 +/- 2.4, p < 0.001) without Cheyne-Stokes respiration and to a significant increase in SaO2min (84 +/- 5% to 89 +/- 2%, p < 0.001). There was no significant change in AHI (1.7 +/- 0.7 to 1.5 +/- 1.6), PSQI (2.4 +/- 0.5 to 2.6 +/- 0.9), and SaO2min (90 +/- 2% to 91 +/- 1%) in patients without CSA. CONCLUSIONS: Cardiac resynchronization therapy leads to a reduction of CSA and to increased sleep quality in patients with HF and sleep-related breathing disorders. This may have prognostic implications in patients receiving CRT.

Comparison of left ventricular lead placement via the coronary venous approach versus lateral thoracotomy in patients receiving cardiac resynchronization therapy.

Cardiac resynchronization therapy (CRT) is a new therapeutic option in patients with heart failure and ventricular conduction delay. We compared the long-term performance of left ventricular (LV) pacing via the coronary venous (CV) approach and a limited lateral thoracotomy (LLT). Data from 81 patients (age 65 +/- 12 years; 52 men, New York Heart Association class 3.0 +/- 0.4, ejection fraction 24 +/- 6%) were retrospectively analyzed for 1 year after implantation of a CRT system. Twenty-five patients received LLT leads and 56 patients received CV leads. Postoperative hospitalization was shorter after CV lead implantation (8 +/- 4 vs 12 +/- 5 days, p <0.01). No significant differences in LV pacing and sensing performance between both approaches were observed after 12 months. Reinterventions were necessary in 7 patients after CV implantation compared with only 1 reintervention (4%) in the LLT group (p = NS). Postoperative chest radiographs revealed an anterior lead position in 11 of 25 patients (44%) in the LLT group versus 3 of 56 patients (5.4%) in the CV group (p = 0.00007). Echocardiographic data demonstrated a significant increase in LV ejection fraction in the CV group (from 26.1 +/- 5.2% to 35.3 +/- 14.3% at 12 months, p <0.001, n = 42) in contrast to the LLT group (from 24.5 +/- 6.2% to 28.5 +/- 7.5% at 12 months, p = NS, n = 16) at 12-month follow-up. Cardiopulmonary exercise testing in 35 patients showed significantly more improvement in peak oxygen consumption after 12 months in the CV group (15.5 +/- 3.1 vs 13.6 +/- 2.6 ml/min/kg at implant, n = 22) compared with the LLT group (12.7 +/- 1.5 vs 11.8 ml/min/kg at implant, n = 13, p = 0.004). At 1-year follow-up the mortality rate was 24% (6 of 25) after LLT lead implantation versus 12.5% (7 of 56) after CV implantation (p = NS). Our data show that the LLT approach for LV lead placement in CRT systems has the advantage of a lower incidence of reinterventions. Hospitalization was longer, increase in functional capacity smaller, and mortality at 1-year follow-up higher, which were potentially related to a more anterior lead position. Therefore, CV leads are preferable to LLT leads.

[Cardiac resynchronization therapy-current status and future perspectives]. / Kardiale Resynchronisationstherapie-aktueller Stand und zukünftige Perspektiven.

BACKGROUND AND AIM: Cardiac resynchronization therapy (CRT) by pacemakers is a new therapeutic principle in the treatment of advanced heart failure. It aims to correct the intracardiac conduction disturbances that are frequently associated with left ventricular dysfunction and thus reduce their negative hemodynamic consequences. In early studies on CRT, acute improvement in cardiac hemodynamics could be shown. Nowadays it is accepted that cardiopulmonary exercise capacity is also improved in the long term with CRT. In addition, reduction of functional mitral regurgitation and reverse left ventricular remodeling have been demonstrated in the majoriy of patients. The results of recent studies demonstrate a reduction in mortality and hospitalizations by CRT. The results of these trials have led to an accepted indication for CRT as an adjunct treatment in heart failure in the updated US guidelines. However, about 30% of patients undergoing device implantation according to currently accepted implant criteria will show no substantial improvement with CRT. Therefore, other indicators to identify therapy responders must be developed in the future, e.g. by using echocardiographic techniques. Moreover, it is yet unclear in how many patients a defibrillator backup is necessary for a CRT patient. This article summarizes the current status of CRT with regard to indications and clinical results. In addition, unresolved issues are discussed and potential developments for the future highlighted.

[Echocardiography in cardiac resynchronization therapy: identification of suitable patients, follow-up and therapy optimization]. / Einsatz der Echokardiographie in der kardialen Resynchronisationstherapie: Identifizierung geeigneter Patienten, Nachsorge und Therapieoptimierung.

BACKGROUND AND AIM: Cardiac resynchronization therapy (CRT) with biventricular stimulation is a new therapeutic option for patients with advanced heart failure and left ventricular asynchrony. The presence of a left bundle branch block morphology in the electrocardiogram is presently the most important selection criterion. Transthoracic echocardiography provides important additional information on the ventricular contraction sequence and the hemodynamic consequences of asynchrony. This may help to identify suitable patients, to improve the selection criteria and to optimize CRT during follow-up. This article discusses the potential techniques and limitations and provides practical guidance for the individual patient follow-up.