Rainer Gradaus

A multicenter experience with novel implantable cardioverter defibrillator configurations in the pediatric and congenital heart disease population.

Both slowed and regularized ventricular rate provide hemodynamic benefits to patients with atrial fibrillation and thus constitute a primary therapeutic goal. The return to sinus rhythm obviously reaches this goal and has been the preferred strategy over several decades. Given that recurrence of atrial fibrillation is frequent in the face of both pharmacological and ablation-based invasive therapy, and that side effects may limit their use, rhythm control approaches may frequently fall short of expected clinical benefits. In that situation, rate control becomes the alternate strategy. In fact, a number of recent clinical trials comparing rhythm and rate control strategies consistently reported net benefits of rate control therapy (see1,2 for review). Accordingly, for many patients rate control is becoming the preferred strategy while rhythm control is being targeted when needed and/or possible.1 Rate control is primarily achieved by drug-induced conduction impairment of the AV node. When this approach fails, ablation-induced third-degree AV block coupled with ventricular pacing may be considered.3,4 Several other approaches are currently under scrutiny: ventricular pacing without AV block, slow pathway ablation, gene therapy, and selective ganglionic parasympathetic stimulation.3 The modulation of AV nodal function by cardiac ganglionic stimulation may prove to be of significant value in heart failure patients in whom antiarrhythmic drug-induced depression of ventricular function must be avoided.5-8 An added benefit is that a normal ventricular activation sequence is maintained. Selective ganglionic stimulation combined with ventricular pacing may provide further benefits by achieving a slowed and regularized ventricular rate in spite of persistent atrial fibrillation.9 The Soos et al. study in the current issue10 raises the possibility that ganglionic stimulation may be feasible with currently available pacemaker technology. The concept of rate control through parasympathetic stimulation is derived from pioneering experimental work showing that selective AV node conduction slowing can be achieved through local cardiac nerve stimulation.11-15 Effective parasympathetic ventricular rate slowing during atrial fibrillation has been reached in animals with nerve stimulation applied endocardially in the vicinity of AV node,16 transvenous catheter stimulation from the coronary sinus,5 and local electrical stimulation of inferior interatrial parasympathetic ganglionated plexus.7-10 In humans, transvenous

Mortality, Morbidity, and Complications in 3,344 Patients with Implantable Cardioverter Defibrillators:

ICDs are the therapy of choice in patients with life‐threatening ventricular arrhythmias. Mortality, morbidity, and complication rates including appropriate and inappropriate therapies are unknown when ICDs are used in routine medical care and not in well‐defined patients included in multicenter trials. Therefore, the data of 3,344 patients ( 61.1 ± 12.1  years ; 80.2% men; CAD 64.6%, dilated cardiomyopathy 18.9%; NYHA Class I–III: 19.1%, 54.3%, 20.1%, respectively; LVEF > 0.50 : 0.234, LVEF 0.30–0.50: 0.472, LVEF < 0.30 : 0.293, respectively) implanted in 62 German hospitals between January 1998 and October 2000 were prospectively collected and analyzed as a part of the European Registry of Implantable Defibrillators (EURID Germany). The 1‐year survival rate was 93.5%. Patients in NYHA Class III and a LVEF < 0.30 had a lower survival rate than patients in NYHA Class I and a preserved LVEF (0.852 vs 0.975, P = 0.0001 ). Including the 1‐year follow‐up, 49.5% of patients had an intervention by the ICD, 39.8% had appropriate ICD therapies, 16.2% had inappropriate therapies. Overall, 1,691 hospital readmissions were recorded. The main causes for hospital readmissions were ventricular arrhythmias (61.3%) and congestive heart failure symptoms (12.9%). Thus, demographic data and mortality of patients treated with an ICD in conditions of standard medical care seems to be comparable and based on, or congruent with, the large secondary preventions trials. When ICDs are used in standard medical care, the 1‐year survival rate is high, especially in patients with NYHA Class I and preserved LVEF. However, nearly half of all patients suffer from ICD intervention. (PACE 2003; 26[Pt. I]:1511–1518)

QRS duration: a simple marker for predicting cardiac mortality in ICD patients with heart failure

Background: Patients resuscitated from ventricular tachyarrhythmias benefit from implantable cardioverter-defibrillators (ICDs) as opposed to medical treatment. Patients with increased QRS duration receiving an ICD in the presence of heart failure are at greatest risk of cardiac death and benefit most from ICD therapy. Objective: To determine whether an increased QRS duration predicts cardiac mortality in ICD recipients. Design: Consecutive patients with heart failure in New York Heart Association functional class III were grouped according to QRS duration (< 150 ms, n = 139, group 1; v ⩾ 150 ms, n = 26, group 2) and followed up for (mean (SD)) 23 (20) months. Patients: 165 patients were studied (80% men, 20% women); 73% had coronary artery disease and 18% had dilated cardiomyopathy. Their mean age was 62 (10) years and mean ejection fraction (EF) was 33 (14)%. They presented either with ventricular tachycardia (VT) or ventricular fibrillation (VF). Main outcome measures: Overall and cardiac mortality; recurrence rates of VT, fast VT, or VF. Results: Mean left ventricular EF did not differ between group 1 (33 (13)%) and group 2 (31 (15)%). Forty patients died (34 cardiac deaths). There was no difference in survival between patients with EF > 35% and ⩽ 35%. Cardiac mortality was significantly higher in group 2 than in group 1 (31.3% at 12 months and 46.6% at 24 months, v 9.5% at 12 months and 18.2% at 24 months, respectively; p = 0.04). The recurrence rate of VT was similar in both groups. Conclusions: Within subgroups at highest risk of cardiac death, QRS duration—a simple non-invasive index—predicts outcome in ICD recipients in the presence of heart failure.

Doppler tissue analysis of mitral annular velocities: evidence for systolic abnormalities in patients with diastolic heart failure

BACKGROUND The presence of signs and symptoms of heart failure (HF), abnormal diastolic function and an ejection fraction > 45%, have been defined as diastolic HF (DHF). However, a cut-off value of 45% for ejection fraction seems arbitrary as mild systolic dysfunction may be overlooked. It was the goal of this study to assess the additive information derived from Doppler tissue imaging for patients with DHF. METHODS As a measure of left ventricular (LV) long-axis function, systolic and diastolic velocities of the mitral annulus (peak, peak early, and peak late) derived from pulsed Doppler tissue imaging were assessed in 36 asymptomatic control subjects, 36 patients with DHF, and 35 patients with systolic HF (SHF). As a measure of overall LV performance, the Tei index (isovolumic contraction time and isovolumic relaxation time divided by ejection time) was assessed. RESULTS In the DHF group, peak systolic annular velocity was reduced (7.1 +/- 1.2 cm/s) as compared with the control group (9.0 +/- 1.2 cm/s, P <.05), and was even lower in the SHF group (5.0 +/- 0.7 cm/s, P <.01 SHF group vs DHF/control groups). The Tei index was increased in the DHF group (0.53 +/- 0.14) in comparison with the control group (0.39 +/- 0.07, P <.05), and was highest in the SHF group (0.94 +/- 0.43, P <.01 SHF group vs control/DHF groups). Using peak systolic annular velocity < 7.95 cm/s as a cut-off value (derived from receiver operating characteristic curve analysis), patients with DHF were separated from control subjects with a sensitivity of 83% and a specificity of 83%. A Tei index > 0.43 separated patients with DHF and control subjects with a sensitivity of 79% and a specificity of 72%. CONCLUSION Systolic long-axis LV function is also impaired in patients with DHF, resulting in feasible diagnosis of DHF by Doppler tissue imaging analysis of LV long-axis function and overall LV function with the Tei index.

Efficacy and Safety of the Initial Use of Stability and Onset Criteria in Implantable Cardioverter Defibrillators

Primary Programming of Stability and Onset Criteria. Introduction: Inappropriate therapies are the most frequent adverse event in patients with implantable cardioverter defibrillators (ICDs). Most ICDs offer a stability criterion to discriminate ventricular tachycardia (VT) from atrial fibrillation and an onset criterion to discriminate VT from sinus tachycardia. The efficacy and safety of these criteria, if used immediately after implantation, is unknown.

ICD leads: design and chronic dysfunctions.

GRADAUS, R., et al.: ICD Leads: Design and Chronic Dysfunctions. The treatment of ventricular tachyarrhythmias has changed over the last 10 years. Implantable cardioverter defibrillators (ICDs), once used only as a last resort therapy, have now become the treatment of choice. This change occurred before the first results of randomized studies on ICD therapy in patients with life‐threatening ventricular tachyarrhythmias were published by the end of 1997. Technological advances of ICD therapy, in particular the development of transvenous leads, were to a large extent responsible for this change. Modern leads are characterized by their multilumen design that incorporates straight wires and coiled conductors into a single electrode body. Conductors and insulation are sheathed with additional insulation layers. The most frequently used insulating materials are silicone, polyurethane, and fluoropolymers. Lead failures are an important complication of ICD therapy. Fractured conductors, compression, creeping, or insulation defects from abrasion can cause such lead dysfunctions. Chronically implanted leads will inevitably have an increased risk of failure due to defects despite all technological advances. In the light of improving survival figures in patients with ventricular tachyarrhythmias and increasing numbers of ICD implantations, lead failures are becoming a clinical problem of ever increasing importance. Therefore, the question of which lead types necessitate extraction when a certain failure occurs and which leads can be left in place. Despite continuous improvements in lead extraction systems and growing experience in their use, the extraction of any pacemaker or ICD lead is associated with some risk of complications. (PACE 2003; 26[Pt. I]:649–657)

Clinical Assessment of a New Real Time 3D Quantitative Coronary Angiography System: Evaluation in Stented Vessel Segments

Background: Foreshortening is a recognized problem that is present in angiography and results from views that are not perpendicular to coronary lesions. This limits visual coronary analysis as well as 2D quantitative coronary angiography systems (QCA). The CardiOp‐B System® is a 3D image acquisition and processing software system designed as an add‐on to conventional X‐ray angiography system. CardiOp‐Bs features include real time and off line analysis with comprehensive 3D reconstruction integrating all of the available information of two 2D vessel angiographies into one 3D image. It was the aim of the study to analyze the accuracy of this new 3D QCA system. Methods: 3D QCA was performed in 50 patients (age 64 ± 10.9; 84% male; LV‐EF 63 ± 16%) measuring 61 stents during high‐pressure inflation (diameter: 2.25–4 mm; length: 8–32 mm). The obtained values (proximal and distal stent diameter, stent length) were correlated with the predefined size of the stents at the used inflation pressure. Results: The linear correlation for the proximal stent diameter was Stentprox= 0.03 + 0.93 × real stent size (r2 = 0.85). The linear correlation for the distal stent diameter was Stentdistal= −0.03 + 0.89 × real stent size (r2 = 0.81). The linear correlation for the stent length was Stentlength= −0.61 + 1.02 × real stent length (r2 = 0.98). Conclusions: The CardiOp‐B System® is a new 3D QCA system with a high linear correlation between the real vessel size and the obtained vessel dimension. It provides real time or off line accurate and comprehensive diagnostic information to the interventional cardiologist without changing the basic coronary angiography procedure.

Atrial Arrhythmias in Long‐QT Syndrome under Daily Life Conditions: A Nested Case Control Study

Background: The long‐QT syndromes (LQTS) are inherited electrical cardiomyopathies characterized by prolonged ventricular repolarization and ventricular arrhythmias. Several genetic reports have associated defects in LQTS‐causing genes with atrial fibrillation (AF). We therefore studied whether atrial arrhythmias occur in patients with LQTS under daily‐life conditions.

Diastolic filling pattern and left ventricular diameter predict response and prognosis after cardiac resynchronisation therapy

Objective: To investigate predisposing factors for cardiac resynchronisation therapy (CRT) response. Design: Single-centre study. Setting: University hospital in Germany. Patients: 122 consecutive patients with heart failure (mean (SD) age 65 (11) years; ischaemic/non-ischaemic 41%/55%; New York Heart Association (NYHA) class 3.1 (0.3); left ventricular ejection fraction 24.4 (8.1)%; QRS width 170 (32) ms, quality of life (QoL) 43.5 (19.2)) with an indication for CRT and demonstrated left ventricular dyssynchrony by echocardiography including tissue Doppler imaging. Interventions: Besides laboratory testing of clinical variables, results of ECG, echocardiography including tissue Doppler imaging, invasive haemodynamics, measures of QoL and of exercise capacity were obtained before CRT implantation and during follow-up. Main outcome measure: Responders were predefined as patients with improvement by one or more NYHA functional class or reduction of left ventricular end-systolic volume by 10% or more during follow-up. Mean (SD) follow-up was 418 (350) days. Results: Overall, 70.5% of patients responded to CRT. Responders had a significantly improved survival compared with non-responders (96.2% vs 45.5%, log-rank p<0.001). On univariate analysis, left ventricular end-diastolic diameter, left ventricular end-systolic diameter (LVESD), E/A ratio, a restrictive filling pattern, mean pulmonary artery pressure, pulmonary capillary pressure, N-terminal pro-brain natriuretic peptide and Vo2max were significant predictors of outcome. On multivariate analyses, LVESD (p = 0.009; F = 7.83), pulmonary capillary pressure (p = 0.015, F = 6.61) and a restrictive filling pattern (p = 0.026, F = 5.707) remained significant predictors of response. Conclusions: Despite treatment according to present guidelines nearly 30% of patients had no benefit from CRT treatment in a clinical setting. On multivariate analyses, patients with an increased left ventricular end-systolic diameter and concomitant diastolic dysfunction had a significantly worse outcome.

Comparison of the Prognostic Usefulness of N-Terminal Pro-Brain Natriuretic Peptide in Patients With Heart Failure With Versus Without Chronic Kidney Disease

In patients with chronic heart failure (CHF), N-terminal pro-brain natriuretic peptide (NT-pro-BNP) predicted poor outcome. Clinical predictors of NT-pro-BNP and its usefulness in the presence of chronic kidney disease (CKD) are largely unknown. A total of 341 patients with stable CHF were enrolled, of whom 183 (54%) had CKD. During a follow-up of 620 +/- 353 days, 57 patients (17%) experienced a cardiac event (cardiac death, need for extracorporeal assist device, or urgent cardiac transplantation), and 64 patients (20%) were rehospitalized because of worsening CHF. NT-pro-BNP was related to New York Heart Association functional class (R = 0.44, p <0.001) and inversely related to ejection fraction (R = -0.52, p <0.001) and glomerular filtration rate (R = -0.32, p <0.001). A cardiac event was independently predicted by NT-pro-BNP (hazard ratio [HR] 1.56, p <0.001), ejection fraction (HR 0.95, p = 0.018), and serum sodium (HR 0.89, p = 0.004). Using receiver-operator characteristic analysis, NT-pro-BNP > or =1,474 pg/ml best separated patients with or without cardiac events. In patients without CKD, outcome was significantly worse in patients with NT-pro-BNP >1,474 pg/ml in comparison to patients with NT-pro-BNP <1,474 pg/ml (event-free survival rate 0% vs 75%; p <0.001). In patients with CKD, outcome was also significantly worse in subjects with NT-pro-BNP >1,474 pg/ml in comparison to those with NT-pro-BNP <1,474 pg/ml (event-free survival rate 48% vs 93%; p <0.001). NT-pro-BNP independently predicted rehospitalization caused by worsening CHF (HR 1.26, p = 0.023), and a cut-off value of 1,474 pg/ml also separated patients with poor and intermediate prognosis in the CKD and non-CKD groups. In conclusion, NT-pro-BNP independently predicted morbidity and mortality in patients with CHF with and without CKD.