New implantable cardiac monitor with three-lead ECG and active noise detection.

BACKGROUND: A new implantable cardiac monitor (BioMonitor, Biotronik) with a continuous remote monitoring option was prospectively implanted in patients with suspected arrhythmias or for therapy control after atrial fibrillation (AF) ablation. A three-lead ECG detection was intended to make the implantation more independent of the implantation site and the electrical heart axis. Because noise is a frequent problem in implantable cardiac monitors, an active noise detection algorithm was implemented. The aim of the trial was to evaluate the clinical performance of the device. METHODS: The device performance was evaluated in a prospective nonrandomized multicenter study with a follow-up of 12 months. Study endpoints were device-related serious adverse events at 3 months, appropriate QRS detection in direct comparison with synchronized Holter ECG recordings, sensitivity and positive predictive value of arrhythmia detection in comparison with Holter ECG and independent of it, and noise burden during the entire follow-up period. RESULTS: The implantation was successful in all 152 patients. Two device-related serious adverse events (pocket infections) occurred by 3 months. The mean QRS amplitude of 0.3 ± 0.2 mV at implantation remained stable over 12 months. QRS sensing performance indicated little over- and undersensing in most patients. More than 80 % of the patients had more than 22 h of noise-free monitoring per day. CONCLUSION: BioMonitor effectively detects patients with bradycardia, tachycardia, AF, or asystole. Active noise detection seems to reduce the transmission of meaningless data without diminishing the positive predictive value of the device.

Single-catheter approach to pulmonary vein reisolation in selected patients : Data from a prospective registry.

BACKGROUND: In addition to different types of single-tip ablation catheters for pulmonary vein (PV) reisolation, a newly developed circular mapping and ablation catheter (nMARQ®) has been available since 2013 and is currently used only in initial PV isolation procedures. In this prospective registry we present feasibility and efficacy data for PV reisolation procedures with a single-catheter approach (nMARQ®) compared with a standard approach using a single-tip ablation catheter and a circular mapping catheter. METHODS: We included 35 carefully selected patients in this prospective registry and assigned them in a 2:1 ratio to undergo either PV reisolation with a single-tip ablation catheter together with a steerable circular mapping catheter (group 1) or with the nMARQ®catheter only (group 2). The recurrence rate was calculated for atrial tachyarrhythmias with a duration of > 30 s during a mean follow-up of 12.7 months. RESULTS: Reisolation of all PVs was achieved in all patients of both groups. In group 2, all gaps could be correctly identified with the nMARQ® catheter. PV isolation was clearly visible on the nMARQ® catheter in all targeted veins. With the nMARQ® catheter the ablation time decreased significantly (6.3 ± 3.0 vs. 18.6 ± 13.9 min, p < 0.05). The recurrence rate of atrial fibrillation did not differ significantly between the two groups (37.5 vs. 45.5 %, p = 0.66). CONCLUSION: In selected patients, a complete PV reisolation procedure is feasible with a singular circular mapping and ablation catheter. The 12-months success rate is comparable to a classic approach with a combination of a single-tip ablation catheter and a circular mapping catheter.

[The Wearable Cardioverter-Defibrillator (WCD)]. / Der tragbare Kardioverter-Defibrillator.

While the implantable cardioverter-defibrillator (ICD) has been proven to be the best choice for patients with long-term risk for sudden cardiac arrest/sudden cardiac death (SCA/SCD), the question is how to manage patients with only temporary risk, e.g., during the guidelines-recommended waiting period until the decision for an ICD can be made. These patient groups should be monitored around the clock to guarantee a lifesaving shock within a few minutes, if necessary.These conditions can be accomplished by the wearable cardioverter-defibrillator (WCD) in the outpatient sector. The WCD is worn on the skin and consists of four nonadhesive ECG electrodes as well as three defibrillation electrodes-two at the back and one at the front-embedded in a garment. The defibrillation unit is connected via a cord and can be worn over the shoulder or on a belt. Cardiac events can be recorded and retrospectively analyzed by the treating physician.The WCD is a safe and effective measure to terminate potentially lethal ventricular tachycardia and ventricular fibrillation. It may be used early after myocardial infarction with reduced left ventricular ejection fraction (LVEF), as well as for patients with acute heart failure in nonischemic cardiomyopathy with uncertain cause and prognosis. In addition, it may be used for patients waiting for heart transplantation, for patients who cannot be implanted an ICD due to comorbidities, and for patients after explantation of their ICD, e.g., because of infection until reimplantation.One may expect that risk stratification of patients with the WCD will lead to even better selection for ICD use.

Spontaneous left atrial reentry tachycardias : radiofrequency ablation and outcome.

AIMS: Spontaneous left atrial reentry tachycardias (LART) in patients without previous cardiac surgical or catheter ablation are rare. Several therapeutic concepts of catheter ablation have been suggested: linear lesions (LL), circumferential pulmonary vein isolation (PVI), and both (LL + PVI). METHODS AND RESULTS: In all, 28 consecutive symptomatic patients with 51 LARTs presented to our institution for catheter ablation. Electroanatomical mapping was performed on 25 patients. Three patients were ablated conventionally during LART; 25 patients (89.3 %) had extensive low-voltage areas in the left atrium (atrial myopathy). One of the following ablation strategies was applied: first, LL (n = 8), second, PVI + LL (n = 11), and third PVI alone (n = 9). Fourteen patients (50 %) had a recurrent arrhythmia during a mean follow-up of 12.2 ± 11.1 months. Six patients presented with a recurrent LART (21.4 %), 4 with LART and atrial fibrillation (Afib) (14.3 %), and 4 with Afib (14.3 %). The recurrence rate of any arrhythmia (LART and Afib) was 37.5 % in the LL group, 44.4 % in the PVI group, and 63.6 % in the PVI + LL group (ns); the recurrence rate of LARTs was 12.5 % in the LL group, 22.2 % in the PVI group, and 63.6 % in the PVI + LL group (p < 0.05). CONCLUSION: Atrial tachyarrhythmia recurrence after ablation of spontaneous LART in mid-term is considerable. Stable LARTs are effectively treated by LL. PVI alone may be an acceptable alternative, especially in patients with unstable LARTs and Afib. However, the risk of recurrent LARTs after a more extensive strategy with PVI and LL is considerable, probably due to proarrhythmic effects of long linear lesions.

The HATCH and CHA2DS 2-VASc scores. Prognostic value in pulmonary vein isolation.

AIMS: The HATCH score describes the risk of paroxysmal atrial fibrillation (Afib) progression, while the CHA2DS2vasc score depicts the risk of thromboembolic events in patients with Afib. We hypothesized that both scores may predict failure of Afib ablation. METHODS AND RESULTS: In all, 449 consecutive patients (65.5 % male, mean age 61.7 ± 10.1 years) who presented to our institution for Afib ablation were investigated. A HATCH score of 0, 1, 2, 3, and ≥ 4 was found in 19.6, 50.3, 9.8, 15.6, and 4.6 % of the patients, respectively. A CHA2DS2vasc score of 0, 1, 2, 3, 4, 5, and > 5 was found in 10.7, 20.9, 25.1, 20.6, 15.0, 4.7, and 3.0 % of the patients, respectively (mean CHA2DS2vasc score, 2.4 ± 1.5). After 618 procedures (1.38 ± 0.55/patient), 84.3 % of patients were free of any atrial arrhythmia after a mean follow-up of 12.7 ± 7.1 months. The freedom of Afib after a single ablation procedure ranged between 50.7 and 60.3 % in patients with HATCH scores between 0 and 3 and dropped to 30.0 % in patients with a HATCH score greater than 3 (p = 0.041). The freedom of Afib after 1.38 procedures per patient ranged between 79.5 % and 88.4 % in patients with a HATCH score between 0 and 3 and was lower with a score of 4 or more (66.7 %, p = 0.064). Pulmonary vein isolation was equally successful in patients with a CHA2DS2vasc score of 5 or lower, but less effective in patients with a score greater than 5 (p = 0.013). CONCLUSION: Pulmonary vein isolation is equally effective in patients with a low-to-moderate risk of disease progression and thromboembolic risk. However, the success rate seems to decrease in patients with high sores.

[Recommendations of the Working Group of Arrhythmias of the German Society of Cardiology on the approach to patients with Riata® and Riata ST® leads (St. Jude Medical). Nucleus of the Working Group of Arrhythmias of the German Society of Cardiology]. / Empfehlungen der Deutschen Gesellschaft für Kardiologie (Arbeitsgruppe Rhythmologie) zum Umgang mit Patienten mit ICD-Elektroden Riata® und Riata ST® der Firma St. Jude Medical. Nucleus der AG Rhythmologie der Deutschen Gesellschaft für Kardiologie.

Riata® and Riata ST® implantable cardioverter defibrillator (ICD) leads (St. Jude Medical, Sylmar, CA) show an increased incidence of insulation defects, particularly "inside-out" lead fracture where inner, separately insulated cables penetrate through the surrounding silicone of the lead body. The exact incidence of Riata® lead problems is not clear and seems to range between 2-4% per year in the first 5 years after implantation according to new registry data. We recommend beyond a detailed information the following care of patients with Riata® and Riata ST® leads: 1) Activation of automatic ICD alerts, 2) remote monitoring with automatic daily alerts whenever possible, 3) monthly ICD controls in patients at high risk (pacemaker dependency, history of ventricular tachyarrhythmias) and high or moderate lead-related risk (8F, 7F single coil), 3-monthly controls in moderate patient and lead-related risk, 3 to 6-monthly controls in low patient and lead-related risk (no bradycardia, no history of ventricular tachyarrhythmia). Every ICD control should include meticulous analysis of oversensing artifacts in stored electrograms (EGMs) of sustained and non-sustained ventricular tachyarrhythmias and registration of EGMs during provocation testing (pectoral muscle activity, arm movements). If electrical abnormalities are observed, reoperation with addition of a new ICD lead is recommended; lead extraction only if indicated according to current guidelines. Fluoroscopy should only be performed if electrical abnormalities are found by an experienced electrophysiologist and a high frame rate and resolution. Management of fluoroscopic abnormalities in the absence of electrical abnormalities is not clear. Therefore, routine fluoroscopy of patients with Riata® leads without electrical abnormalities is not recommended.

VT ablation in heart failure.

Ventricular tachycardias (VT), shocks, and clusters of shock are ominous signs in patients with implantable cardioverter-defibrillators and herald an increased risk of hospitalization and mortality. VT clusters have been associated with aggravation of heart failure (19%), acute coronary events (14%), and electrolyte imbalance (10%). Yet, any association of potential causative factors and aggravation of VT is vague. Maybe, in patients with any substrate for re-entry, progressive aggravation of ventricular dysrhythmias is to be expected. The high recurrence rate of electrical storm despite antiarrhythmic drug therapy supports this view. The optimal timing of VT ablation is unknown, but current convention is to perform VT ablation after shock clusters or incessant VT has occurred. Preemptive VT ablation before VT has occurred is rarely performed (only in 15% of active centers) and the majority of centers never perform VT ablation even after the first shock. Such practice is within guidelines that recommend VT ablation only in ICD patients with recurrent or incessant VT. However, there is strong data in support of preemptive VT ablation.

Surface and intracardiac ECG for discriminating conduction disorders after CoreValve implantation.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) has been developed to minimize operative morbidity and mortality in high-risk symptomatic patients unfit for open surgery. With the proximity of the aortic valve annulus to the conduction system there is, however, an unknown risk of conduction disturbances necessitating monitoring and often cardiac pacing. MATERIALS AND METHODS: We enrolled 50 consecutive patients from January 2007 to 2008 in our prospective evaluation of conduction disturbances measured by surface and intracardiac ECG recordings. Baseline parameters, procedural characteristics as well as twelve-lead surface ECG and intracardiac conduction times were revealed pre-interventionally, after TAVI and at 7-day follow-up. RESULTS: TAVI was performed successfully in all patients. During 7 days of follow-up the rate for first-degree AV block raised from 14% at baseline to 44% at day 7 (p < 0.001), while rates for type II second- and third-degree were 0 versus 8% (p < 0.001) and 0 versus 12% (p < 0.001), respectively. Similarly, the prevalence of new left bundle branch block (LBBB) rose from 2 to 54% (p < 0.001). Intracardiac measurements revealed a prolongation of both AH and HV interval from 123.7 ± 41.6 to 136.6 ± 40.5 ms (p < 0.001) and from 54.8 ± 11.7 to 71.4 ± 20.0 ms (p < 0.001), respectively. Pacemaker implantation at a mean follow-up of 4.8 ± 1.2 days was subsequently performed in 23 patients (46%) due to complete AV block (12%) and type II second-degree AV block (8%) while another 13 patients (26%) received a pacemaker for the combination of new LBBB with marked HV prolongation. The high rate of first-degree AV block was primarily driven by an increase in HV interval. CONCLUSION: Cardiac conduction disturbances were common in the early experience with CoreValve implantation necessitating close surveillance for at least 1 week.

Ventricular tachycardia and sudden death after primary PCI-reperfusion therapy: impact on primary prevention of sudden cardiac death.

BACKGROUND: Current approaches to coronary artery disease (CAD) and acute myocardial infarction (MI) may not be well represented in most primary prevention trials of sudden cardiac death (SCD). METHODS: The contemporary and ongoing registry of the Rostock infarction network (Drip & Ship) represents a well-defined cohort of patients subjected to percutaneous coronary intervention (PCI) for ST-elevation infarction (STEMI) and served as the database for both candidates for an ICD for primary prevention of SCD and for sudden death (SCD) or ventricular tachycardia (VT) during follow-up. RESULTS: A total of 855 consecutive patients were treated with PCI for STEMI or NSTEMI in the region of Rostock (Germany) between 2001 and 2004. While all cause mortality was still 17.2%, the SCD rate was low at 1.3% during 728 ± 366 days of follow-up. Within that time 85 patients (9.9%) developed an indication for ICD therapy due to an impaired LV function (LVEF ≤ 35%) and heart failure. Univariate predictors of an ICD indication were delayed reperfusion (p = 0.001), a high creatine kinase (CK) max (p = 0.009), a persistent wide QRS complex (p = 0.001), previous cerebrovascular events (p = 0.033), and chronic renal failure (p = 0. 001). However, only 16.5% of these patients qualifying for an ICD actually received an ICD; nevertheless, the actual SCD rate was only 3.5%, while 5.4% (46 patients) suffered VTs or ventricular fibrillation (VF). The SCD/VT rate in the entire infarct population was associated with time to reperfusion (0.032), left bundle-branch block (0.002), a longer history of CAD (0.032), and VT during follow-up. CONCLUSION: While mortality in patients with STEMI is still alarming even with PCI, the risk of SCD may be considerably decreased even in patients with an LVEF below 35%. With the current approach to primary prevention of sudden cardiac death, approximately 10% of postinfarction patients qualify for ICD therapy; however this may only reach a quarter of patients prone to SCD.

[Antiarrhythmic therapy with ß-receptor antagonists]. / Antiarrhythmische Therapie mit ß-Rezeptor-Antagonisten.

ß-Blockers are an essential component of medical therapy in patients with ischemic heart disease or cardiac dysfunction of any genesis. They have an effect at the level of the sinus and the atrioventricular node, as well as on the atrial and ventricular refractory period of the myocardium. Overall, there are complicated antifibrillatory effects which are involved in the reduction of morbidity and mortality of this the therapy. According to the guidelines, it is important to uptitrate to highest tolerated dose. In patients with atrial fibrillation, antiadrenergic therapy should be the first line treatment; if well tolerated, then ß-blockers alone or as a combination with an antiarrhythmic drug is preferable. Future prospective studies on the antiarrhythmic effects in this therapeutic area should include comparisons of different α - and ß-selective active substances. Increasing knowledge of the differential therapy with the available active substances including intravenously applicable short-acting ß-blockers, e.g., in intensive care therapy - should distinguish the different therapeutic effects.

[The patient with chronic heart failure]. / Der Patient mit chronischer Herzinsuffizienz.

An expansion of the indications for the implantation of defibrillators (ICD) has not occurred as such in recent years. Nevertheless, an increase in the number of implantation figures can be expected due to the aging population and an increasing recruitment of undersupplied regions in upcoming years. Although the first defibrillator was implanted over 20 years ago in Germany and that ICD therapy is considered as the medical standard in secondary and primary prophylaxis, there are still basic questions that can only be prospectively clarified: (1) when is the right point in time for ICD implantation? (2) Can predictors, especially those with a negative predictive value, be used to exclude patients from ICD therapy? (3) Should risk stratification, which documents the current risk for a single point in time during the illness like a snapshot, more strongly reflect the development over time of the risk? In this case, it is likely that a rethinking of risk stratification, in general, to risk stratification in the sense of observation would be necessary. An adjuvant therapy in the sense of ablation of ventricular tachycardia (VT) or antiarrhythmic therapy for primary prevention of frequently occurring episodes seems to be advised based on current data. However, the right point in time for a complementary intervention is still not clear.

Antitachycardia pacing for rapid VT during ICD charging: a method to prevent ICD shocks.

In patients with ICDs, rapid VTs are usually treated with shocks. It is unknown, if antitachycardia pacing (ATP) delivered once for rapid VT during capacitor charging can avoid painful shocks without increasing the risk of syncope. In patients in whom rapid monomorphic VT (cycle length 300-220 ms) could be reproducibly induced during predischarge ICD testing, the success of cardioversion (defibrillation threshold plus 10 J) and a single ATP attempt (burst with 8 or 16 stimuli) was compared using a randomized crossover study design. Consciousness of the patients was checked by the signal from a button constantly pushed by the patient. In 20 patients (ejection fraction 0.50 +/- 0.19) rapid VTs (253 +/- 26 ms) were reproducibly induced. A single burst successfully terminated 11 (55%) of 20 rapid VTs, 6 episodes could not be terminated with a single burst pacing and 3 VTs accelerated. Rapid VTs not terminated by ATP were significantly faster than those that could be terminated (246 vs 258 ms, P = 0.026). Cardioversion (19 +/- 3 J) terminated the VTs in all cases. No patient suffered syncope during rapid VTs. A single ATP may terminate rapid VT with cycle lengths < 300 ms in 55% of patients without increasing the risk of syncope. Therefore, in rapid VTs one attempt of ATP may be suitable as an additional therapy option during ICD capacitor charging to avoid painful shocks without compromise of safety. Thus, future ICDs should implement the option of ATP during charging of capacitors.

Ventricular tachycardias above the initially programmed tachycardia detection interval in patients with implantable cardioverter-defibrillators: incidence, prediction and significance.

OBJECTIVES: This retrospective study was performed to provide data on ventricular tachycardias (VT) with a cycle length longer than the initially programmed tachycardia detection interval (TDI) in patients with implantable cardioverter defibrillators (ICDs). BACKGROUND: It has been clinical practice to program a safety margin of 30 to 60 ms between the slowest spontaneous or inducible VT and the TDI. METHODS: Baseline characteristics of 659 consecutive patients with ICDs were prospectively; follow-up information was retrospectively collected. RESULTS: During a mean follow-up of 31+/-23 months, 377 patients (57.2%) had at least one recurrent VT or ventricular fibrillation; 47 patients (7.1%) suffered 61 VTs above the TDI. The risk of a VT above the TDI ranged between 2.7% and 3.5% per year during the first four years after ICD implantation. The difference between the cycle length of the slowest VT before ICD implantation, spontaneous or induced, and the first VT above TDI was 108+/-58 ms. Fifty-four VTs (88.5%) above the TDI were associated with significant clinical symptoms (angina or palpitation 63.9%, heart failure 6.6% and syncope 8.2%). Six patients (9.8%) had to be resuscitated. Kaplan-Meyer analysis identified New York Heart Association class II or III (p = 0.021), ejection fraction < 0.40 (p = 0.027), spontaneous (p<0.001) or inducible (p<0.001) monomorphic VTs and the use of class III antiarrhythmic drugs (amiodarone, p<0.001; sotalol, p = 0.004) as risk predictors of VTs above the TDI. The risk of recurrent VTs above TDI was 11.8%, 12.5% and 26.6% during the first, second and third year after first VT above TDI, respectively. CONCLUSIONS: The risk of VTs above the TDI is significantly increased in some patients, and many VTs above TDI cause significant clinical symptoms. A larger safety margin between spontaneous or inducible VTs and the TDI seems to be necessary in selected patients. This is in conflict with an increased risk of inadequate episodes and demands highly specific and sensitive detection algorithms in these patients.

Clusters of ventricular tachycardias signify impaired survival in patients with idiopathic dilated cardiomyopathy and implantable cardioverter defibrillators.

OBJECTIVES: This retrospective study was undertaken to provide data on occurrence, significance and therapy of ventricular tachyarrhythmia (VT) clusters (VTCs) in patients with dilated cardiomyopathy (DCM) and implantable cardioverter defibrillators (ICDs). BACKGROUND: Data on the clinical significance of VTCs are lacking in patients with DCM and ICDs. METHODS: Baseline characteristics of 106 consecutive patients with DCM and ICDs were prospectively collected, and chart reviews and episode data retrospectively analyzed. A VTC was defined as > or =3 sustained VTs/24 h. RESULTS: During a mean follow-up of 33+/-23 months, 73 patients (68.9%) had recurrent VT or ventricular fibrillation (VF), 43 patients (40.6%) suffered only single VTs and 30 patients (28.3%) experienced 52 clusters of VTs. Actuarial survival free of VT or VF was 44.6%, 33.0% and 26.5%, and survival free of VTC was 77.3%, 72.2% and 67.1% after one, two and three years, respectively. Independent predictors of VT clusters were heart failure before ICD implantation (p = 0.033), presenting monomorphic VT (p = 0.044), EF <0.40 (p = 0.014) and inducible mVT, especially with right bundle branch block and superior axis configuration (p<0.001). Survival free of recurrent VTCs was 50.8%, 38.1% and 19.0% after one, two and three years, respectively. Once a VTC had occurred, only 56.7%, 46.4%, 30.9% and 15.5% of patients survived and were not transplanted after one, two, three and four years, respectively. Survival was even more reduced if a VTC was associated with cardiac decompensation: 65.6% and 21.9% after one and two years, respectively. CONCLUSIONS: Despite antiarrhythmic intervention, clusters of VTs occur and recur frequently in patients with DCM. They signify impaired survival, especially if they are associated with cardiac decompensation, and may be a harbinger of progressive myocardial deterioration rather than a primarily arrhythmic problem. The benefit of ICD therapy may therefore be low in these patients.

Efficacy and safety of the initial use of stability and onset criteria in implantable cardioverter defibrillators.

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. METHODS AND RESULTS: In a case control study, 87 patients in whom stability and onset criteria had been activated immediately after ICD implantation were matched to 87 patients in whom these criteria had not been activated. The groups were matched for known predictors of inappropriate therapies. With stability and onset criteria off, 24 patients (28%) received inappropriate therapies due to atrial fibrillation (n = 14) or sinus tachycardia (n = 11); with stability and onset on, only 11 patients (13%) were treated by the ICD due to atrial fibrillation (n = 5) or sinus tachycardia (n = 7) (log rank: P = 0.029). Five patients suffered inappropriate therapies despite the fact that onset (n = 4) or stability (n = 1) criteria were not fulfilled once tachycardias continued for a prespecified duration. Only one patient experienced a failure to detect VT due to the onset criterion; none because of stability. CONCLUSION: The immediate use of stability and onset criteria after ICD implantation reduces inappropriate therapies due to atrial fibrillation and sinus tachycardia. Because of the potential for underdetection of VT, this approach should be limited to tachycardia rates hemodynamically tolerated by the patient.

Potential benefit from implantable cardioverter-defibrillator therapy in patients with and without heart failure.

BACKGROUND: Whether patients with heart failure derive a benefit from therapy with implantable cardioverter-defibrillators (ICDs) has been questioned. The purpose of this study was to investigate whether New York Heart Association (NYHA) functional class had an impact on the potential benefit from ICD therapy as assessed from data stored in the memory of ICDs. METHODS AND RESULTS: Between 1989 and 1996, 603 patients (77% men; 59% with coronary artery disease and 16% with dilated cardiomyopathy; age, 57+/-13 years; ejection fraction, 44+/-18%) were treated with an ICD with extended memory function (storage of electrograms and/or RR intervals from treated episodes) in combination with endocardial lead systems. The stages of heart failure (NYHA functional class I through III) at implantation were correlated with overall mortality and the recurrence of fast ventricular tachyarrhythmias (>240 bpm) during follow-up. The potential benefit of the device was estimated as the difference between overall mortality and the hypothetical death rate had the device not been implanted. The latter was based on the recurrence of fast and, without termination by the devices, presumably fatal ventricular tachyarrhythmias. In the overall group, a significant difference between hypothetical death rate and overall mortality was observed (13.9%, 23.5%, and 26.6% at 1, 3, and 5 years, respectively) that suggested a benefit from ICD implantation. In patients in NYHA class I, the estimated benefit, which increased over time, was 15.2%, 29.2%, and 35.6% after 1, 3, and 5 years, respectively. In patients in NYHA class II or III, the estimated benefit increased until the third year (21.8% and 21.9%, respectively) and then remained constant until the fifth year (22.9% and 23.8%, respectively). Even those patients in NYHA class III with a history of decompensated heart failure benefited from ICD implantation. CONCLUSIONS: Analysis of stored ECG data suggests that in patients with a history of ventricular tachycardia or ventricular fibrillation, ICD therapy may lead to a prolongation of life in NYHA classes I through III. The initial benefit is greatest in patients in NYHA class II and class III, but the estimated benefit might persist longest for patients in NYHA class I.

Basal growth hormone levels in women are positively correlated with high-density lipoprotein cholesterol and apolipoprotein A-I independently of insulin-like growth factor 1 or insulin.

Previous studies in growth hormone (GH)-deficient or acromegalic patients yielded contradictory results on the effect of GH on lipoprotein metabolism. In a cross-sectional study, we analyzed the relationships between unstimulated GH, insulin-like growth factor 1 (IGF1), insulin, and lipoprotein metabolism in 44 non-obese young women. On univariate analysis, basal serum levels of GH correlated positively with triglycerides, high-density lipoprotein (HDL) cholesterol, apolipoprotein A-I (apoA-I) and apoA-II and negatively with lipoprotein lipase (LPL) activity. These associations remained significant on multivariate analyses that, in addition to GH, took into account the effects of insulin or C-peptide, as well as the effects of total, protein-bound, or free IGF1. In most cases, the relationships of these lipid parameters with insulin/C-peptide and IGF1 and its free or protein-bound subfractions were opposite of those with GH and not significant. Thus, GH appears to regulate the metabolism of HDL and triglycerides independently of IGF1 and insulin.