Gender-Related Differences in Outcomes of Patients with Cardiac Resynchronization Therapy.

BACKGROUND: Gender-related differences (GRD) exist in the outcome of patients with cardiac resynchronization therapy (CRT). OBJECTIVES: To assess GRD in patients who underwent CRT. METHODS: A retrospective cohort of 178 patients who were implanted with a CRT in a tertiary center 2005-2009 was analyzed. Primary outcome was 1 year mortality. Secondary endpoints were readmission and complication rates. RESULTS: No statistically significant difference was found in 1 year mortality rates (14.6% males vs. 11.8% females, P = 0.7) or in readmission rate (50.7% vs. 41.2%, P = 0.3). The complication rate was only numerically higher in women (14.7% vs. 5.6%, P = 0.09). Men more often had CRT-defibrillator (CRT-D) implants (63.2% vs. 35.3%, P = 0.003) and had a higher rate of ischemic cardiomyopathy (79.2% vs. 38.2%, P < 0.001). There was a trend to higher incidence of ventricular fibrillation/ventricular tachycardia in men before CRT implantation (29.9% vs. 14.7%, P = 0.07%). A higher proportion of men upgraded from implantable cardioverter defibrillator (ICD) to CRT-D, 20.8% vs. 8.8%, P = 0.047. On multivariate model, chronic renal failure was an independent predictor of 1 year mortality (hazard ratio [HR] 3.6; 95% confidence interval [95%CI] 1.4-9.5), CRT-D had a protective effect compared to CRT-pacemaker (HR 0.3, 95%CI 0.12-0.81). CONCLUSIONS: No GRD was found in 1 year mortality or readmission rates in patients treated with CRT. There was a trend toward a higher complication rate in females. Men were implanted more often with CRT-D and more frequently underwent upgrading of ICD to CRT-D.

Association between Red Cell Distribution Width and Mortality after Cardiac Resynchronization Therapy.

BACKGROUND: Cardiac resynchronization therapy (CRT) is a non-pharmacological option for patients with heart failure and interventricular dyssynchrony. Elevated red cell distribution width (RDW) reflects higher size and heterogeneity of erythrocytes and is associated with poor outcome in patients with chronic heart failure. OBJECTIVES: To examine the association between RDW levels and outcomes after CRT implantation. METHODS: We conducted a cohort analysis of 156 patients (126 men, median age 69.0 years) who underwent CRT implantation in our institution during 2004-2008. RDW was measured at three time points before and after implantation. Primary outcome was defined as all-cause mortality, and secondary outcome as hospital re-admissions. We investigated the association between RDW levels and primary outcome during a median follow-up of 61 months. RESULTS: Ninety-five patients (60.9%) died during follow-up. Higher baseline RDW levels were associated with all-cause mortality (unadjusted HR 1.35, 95% CI 1.20-1.52, P < 0.001). On multivariate analysis adjusted for clinical, electrocardiographic and laboratory variables, baseline RDW levels were associated with mortality (HR 1.33, 95%CI 1.16-1.53). RDW levels 6 months and 12 months post-implantation were also associated with mortality (HR 1.22, 95%CI 1.08-1.38, P = 0.001; and HR 1.15, 95% CI 1.01-1.32, P = 0.02, respectively). Patients who were re-admitted to hospital during follow-up (n = 78) had higher baseline RDW levels as compared to those who were not (14.9%, IQR 14.0, 16.0% vs. 14.3%, IQR 13.7, 15.0%, respectively, P = 0.03). CONCLUSION: An elevated RDW level before and after CRT implantation is independently associated with all-cause mortality.

Association of time of occurrence of electrical heart storms with environmental physical activity.

AIM: Many publications in recent decades have reported a temporal link between medical events and environmental physical activity. The aim of this study was to analyze the time of occurrence of electrical heart storms against levels of cosmological parameters. METHODS: The sample included 82 patients (71 male) with ischemic cardiomyopathy treated with an implantable cardioverter defibrillator at a tertiary medical center in 1999-2012 (5,114 days). The time of occurrence of all electrical heart storms, defined as three or more events of ventricular tachycardia or ventricular fibrillation daily, was recorded from the defibrillator devices. Findings were analyzed against data on solar, geomagnetic, and cosmic ray (neutron) activity for the same time period obtained from space institutions in the United States and Russia. RESULTS: Electrical storms occurred in all months of the year, with a slight decrease in July, August, and September. Most events took place on days with lower-than-average levels of solar and geomagnetic activity and higher-than-average levels of cosmic ray (neutron) activity. There was a significant difference in mean daily cosmic ray activity between the whole observation period and the days of electrical storm activity (P = 0.0001). CONCLUSION: These data extend earlier findings on the association of the timing of cardiac events and space weather parameters to the most dangerous form of cardiac arrhythmia-electric storms. Further studies are needed to delineate the pathogenetic mechanism underlying this association.

Pacemaker implantation after transcatheter aortic valve implantation.

Thirty- to 35% of patients after transcatheter aortic valve implantation undergo implantation of a permanent pacemaker (PPM) because of development of atrioventricular block (AVB) or development of a condition with high risk of progression to AVB. There are insufficient data regarding long-term follow-up on pacing dependency. From February 2009 to July 2011, 191 transcatheter aortic valve implantation procedures were performed at the Rabin Medical Center (125 CoreValve and 66 Edwards SAPIEN). Thirty-two patients (16.7%) received a PPM (30 with CoreValve and 2 with Edwards SAPIEN). Data from the pacemaker clinic follow-up was available in 27 patients. After a mean follow-up of 52 weeks (range, 22 to 103), only 8 (29%) of 27 patients were pacing dependent. The indication of PPM in these 8 patients was complete AVB. In conclusion, in our center, the rate of PPM implantation was 16%, which is lower than that reported in the published works. Only 29% of those patients implanted with PPM were pacemaker dependent. Further studies are necessary to define reliable predictors for long-term pacing.

Clinical experience of two Israeli medical centers with the implantable loop recorder in patients with syncope: from diagnosis to treatment.

BACKGROUND: The implantable loop recorder (ILR) is an important tool for the evaluation of unexplained syncope, particularly in cases of rarely occurring arrhythmia. OBJECTIVES: To review the clinical experience of two Israeli medical centers with the ILR. METHODS: We reviewed the medical records of patients with unexplained syncope evaluated with the ILR at Rabin Medical Center (2006-2010) and Wolfson Medical Center (2000-2009). RESULTS: The study group included 75 patients (44 males) followed for 11.9 +/- 9.5 months after ILR implantation. Patients' mean age was 64 +/- 20 years. The ILR identified an arrhythmic mechanism of syncope in 20 patients (17 bradyarrhythmias, 3 tachyarrhythmias) and excluded arrhythmias in 12, for a diagnostic yield of 42.7%. It was not diagnostic in 17 patients (22.7%) at the time of explant; 26 patients (34.7%) were still in follow-up. In two patients ILR results that were initially negative were reversed by later ILR tracings. The patients with bradyarrhythmias included 9 of 16 (56.3%) with surface electrocardiogram conduction disturbances and 2 of 12 (16.7%) with negative findings on carotid sinus massage. All bradyarrhythmic patients received pacemakers; the seven patients for whom post-intervention data were available had no or mild symptoms. CONCLUSIONS: The ILR has a high diagnostic yield. Pre-ILR findings correlating with the ILR results are conduction disturbances (positive predictor of arrhythmia) and negative carotid sinus massage results (negative predictor of arrhythmia). Proper patient instruction is necessary to obtain accurate results. Caution is advised when excluding an arrhythmia on the basis of ILR tracings, and long-term follow-up is warranted.

Implantable cardioverter defibrillator with and without defibrillation threshold testing.

BACKGROUND: Defibrillation threshold (DFT) testing at the time of implantable cardioverter defibrillator (ICD) insertion is performed routinely. This practice is being reconsidered due to doubts about its ability to improve ICD efficacy and evidence that survival may not be affected by the test. OBJECTIVES: To compare the outcome of ICD recipients who underwent DFT testing and those who did not. METHODS: A total of 213 eligible patients were implanted with an ICD between 2004 and 2009. DFT testing was performed in 80 of them. We compared total mortality, appropriate and inappropriate ICD shocks, and anti-tachycardia pacing (ATP) events between DFT and non-DFT patients during a follow-up of 2 years. RESULTS: On comparing the DFT and non-DFT groups, we found a 2 year mortality rate of 7.5% versus 8.3%, respectively (P = 0.8). Furthermore, 20.7% of patients in the DFT group and 12.4% in the non-DFT group had at least one episode of ICD shock (P = 0.15). With regard to ICD treatment (ICD shocks or ATP events), 57.7% in the DFT group and 64.2% in the non-DFT group received appropriate treatments (P = 0.78). CONCLUSIONS: No significant differences in the incidence of 2 year mortality or percentage of ICD treatment emerged between the DFT and non-DFT groups.

Prinzmetal angina in the differential diagnosis of syncope.

Prinzmetal (variant) angina may be associated with cardiac arrhythmias that can deteriorate to fatal ventricular arrhythmias. We present 2 patients with syncope where vasospastic angina and severe ventricular arrhythmias were found to be responsible for the syncopal episodes.

Right ventricular pacing increases tricuspid regurgitation grade regardless of the mechanical interference to the valve by the electrode.

AIMS: The effect of right ventricular (RV) pacing on tricuspid regurgitation (TR) is debatable and is presumed to be related to an interference with valve closure by the electrode. The aim of the study was to determine the impact of pacing per se on TR grade. METHODS AND RESULTS: The study group included 23 clinically stable patients (13 males; mean age 78 +/- 12 years) with a permanent pacemaker at the RV apex (83% DDD mode) and normal left ventricular function. They were all non-dependent on pacing and were otherwise in sinus rhythm. None had a primary dysfunction of the tricuspid valve. TR grade and RV size were assessed in two consecutive echo studies with and without active RV pacing. Results showed that active RV pacing was associated with an increase in TR severity (TR vena contracta: 0.4 +/- 0.2 vs. 0.2 +/- 0.2 cm, P < 0.001; TR jet area: 4.1 +/- 2.3 vs. 2.3 +/- 1.8 cm(2), P < 0.001). This was also reflected in a significant decrease in the number of patients with mild TR (P = 0.003) and increase in the number with moderate regurgitation (P = 0.02). There was no change in RV areas with pacing. CONCLUSION: Active RV pacing is associated with a significant increase in TR grade. This effect is not induced by acute changes in the RV area and is unrelated to an interference with leaflet closure by the electrode.

Sick sinus syndrome in a patient with extensive cardiac lipomatosis (sinus node dysfunction in lipomatosis).

We present a case of a 45-year-old man with an incidental and longstanding diagnosis of extensive mediastinal and cardiac lipomatosis. Along the years, he had experienced various arrhythmias, mainly bradyarrhythmias, mostly asymptomatic. Recently after documenting a sinus pause of 6 seconds and runs of nonsustained ventricular tachycardias, he underwent an implantation of a cardioverter-defibrillator. There are many reports of cardiac lipomatosis in the literature, including reports of related ventricular arrhythmias, some of which are fatal. (PACE 2010; 513-515).

A life-threatening arrhythmia induced by inappropriate activation of an implantable cardioverter defibrillator.

We describe an unusual case of near fatal inappropriate implantable cardioverter defibrillator therapies due to atrial oversensing by a newly implanted ventricular lead. Chest X-ray revealed dislodgement of the active fixation lead to the tricuspid annulus area explaining the atrial oversensing and intermittent ventricular therapies.

Cardiac defibrillator implantation via persistent left superior vena cava facilitated by a coronary sinus delivery system.

Persistent left superior vena cava (PLSVC) is a benign vascular anomaly that complicates pacemaker or implantable cardioverter defibrillator (ICD) lead implantation. Thus far, right ventricular lead implantation via PLSVC has been mostly accomplished by forming a U-shaped stylet, necessitating considerable manoeuvring depending on the heart size and geometry. In this article we report a technique of ICD lead implantation via PLSVC, using a coronary sinus delivery system as used today in cardiac resynchronization therapy.

Timing of life-threatening arrhythmias detected by implantable cardioverter-defibrillators in relation to changes in cosmophysical factors.

BACKGROUND: Studies have linked the natural history of many pathologies with environmental physical activity. This study investigated the relationship between the occurrence of ventricular tachycardia/fibrillation (VT/VF) recorded by implantable cardioverter defibrillators (ICD) and geomagnetic and cosmic ray (neutron) activity. METHODS: The study group included 85 patients (73 men) with cardiomyopathy (80% ischemic) who underwent ICD placement in the years 1995-2006; 74% had a left ventricular ejection fraction of < 30%. Data on the days on which VT/VF occurred (total number of days: 284) and the days on which the patients were treated (total number of treatments: 580) were collected from the ICD records. The findings were analyzed against levels of geomagnetic activity (GMA) (I degree -IV degree) and cosmic ray activity (CRA), derived from international observatories, on the same days and throughout the study period. RESULTS: On days of VT/VF, daily values of GMA level averaged 1.5 +/- 0.7, consistent with level I degree (quiet). The ratios of daily VT/VF episodes and treatment to GMA level for the whole study period were as follows: 1.2 level I; 0.9 level II; 0.69 level III; 0.78 level IV (r = -0.974; p = 0.02). Mean CRA on days of VT/VF was 9246.8 +/- 299.0 imp/min, and for all 4383 days studied, 8805.33 +/- 411.4 imp/min (p < 0.0001). CONCLUSIONS: In patients with predominantly ischemic cardiomyopathy and severe left ventricular dysfunction, VT/VF occurs more often on days of low GMA and high CRA. Further studies are needed to determine the underlying mechanism of the effect of neutron activity on cardiac electrical instability.

Inflammatory biomarkers are not predictive of intermediate-term risk of ventricular tachyarrhythmias in stable CHF patients.

BACKGROUND: Elevated levels of inflammatory biomarkers and brain natriuretic peptide (BNP) are associated with increased mortality in patients with heart failure (HF). HYPOTHESIS: : The aim of the current study was to assess the correlation between circulating biomarkers and ventricular tachyarrhythmias among patients with HF. METHODS: Blood samples from 50 stable ambulatory HF patients with moderate to severe systolic left ventricular (LV) dysfunction and an implantable cardioverter defibrillator (ICD) were analyzed for interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), high-sensitivity C-reactive protein (hsCRP) and BNP. Thereafter, the patients were followed for a mean period of 152 +/- 44 days, during which ventricular tachyarrhythmias were recorded by the ICDs. RESULTS: Follow-up data were obtained from 47 patients. Of them, 45 (96%) had ischemic cardiomyopathy, 38 (81%) had New York Heart Association class I-II, 43 (91%) were males, and the mean age was 68.6 +/- 11.1 years. During follow-up, 5 patients (11%) had nonsustained ventricular tachycardia (NSVT), 6 patients (13%) had sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) and 36 patients (76%) had no events. The circulating biomarkers' levels upon enrollment were not significantly different between patients who subsequently had NSVT or VT/VF and patients who were free of events. CONCLUSIONS: No correlation was found between plasma levels of IL-6, TNF-alpha, hsCRP and BNP and ventricular arrhythmic events among stable HF patients during an intermediate term follow-up of 5.1 months. Further studies are still required to assess the association between these biomarkers and long-term risk of ventricular tachyarrhythmia.

Urgent cardiac resynchronization therapy in patients with decompensated chronic heart failure receiving inotropic therapy. A case series.

BACKGROUND: It remains unknown whether patients with severe decompensated class IV heart failure (HF) receiving intravenous inotropic treatment benefit from cardiac resynchronization therapy (CRT). METHODS: We identified patients who underwent urgent CRT implantation due to decompensated class IV HF necessitating intravenous inotropic therapy. RESULTS: Of 10 patients with chronic ischemic cardiomyopathy (median QRS duration of 170 ms), CRT implantation was associated with symptomatic improvement in 8 patients. The mortality rate was 50% during a median follow-up of 9.5 months, with a median CRT-to-death duration of 6 months. CONCLUSIONS: CRT was feasible among class IV patients receiving inotropic treatment and was associated with clinical improvement.

Temporal relationship of implantable cardioverter defibrillator discharges and environmental physical activity.

BACKGROUND: Studies by our group have shown an inverse relationship between sudden death and cardiac rhythm disturbances and environmental levels of geomagnetic activity (GMA). The aim of this study was to use the precise data provided by automatic implantable cardioverter defibrillators (ICDs) regarding the onset of ventricular fibrillation and ventricular tachycardia to link these events to GMA level. PATIENTS AND METHODS: The study group included 25 patients (22 men; 22 with ischemic cardiomyopathy) aged 28-81 years in whom an ICD had been implanted between 1995 and 2004. Patients were referred to the cardiac intensive care unit after each event that induced one or more discharges. The number of events and the day on which they occurred were recorded. Data on GMA and other cosmophysical parameters were obtained from the U.S. National Geophysical and Space Service Centers and the Russian Academy of Sciences. GMA levels, graded from I (quiet) to IV (stormy) in the middle latitutes, were recorded for 1974-2003 (10,954 days) and for each day on which an ICD discharge occurred. RESULTS: A total of 402 discharges were recorded on 137 days during the study period. Forty-six percent of the discharges took place on days of GMA I, compared with 38% - II, 13% - III, and 3% - IV. The daily distribution of GMA was as follows: level I - 35.2%, II - 37.3%, III - 21.86%, IV - 5.61%. Comparison of ICD discharge days and actual multiyear levels of GMA (in percent) yielded a ratio of 1.326 for GMA I, 1.076 - II, 0.459 - III, 0.390 - IV. There was a significant inverse correlation between GMA level and number of discharges (r =-0.97, P = 0.03) and days of treatment (r =-0.96, P = 0.039), and a significant difference between ICD discharges on days of GMA I and GMA II-IV (chi(2)= 5.05, P = 0.02). CONCLUSION: The higher number of ICD discharges on days of lowest GMA may be explained by a possible antiarrhythmic effect of GMA. Environmental arrhythmogenic factors that act inversely to GMA may be activated at times of low GMA.

Reperfusion-related polymorphic ventricular tachycardia as a possible mechanism of sudden death in patients with anomalous coronary arteries.

We describe a patient with anomalous origin of the left coronary artery in whom polymorphic ventricular tachycardia developed immediately after an episode of chest pain with ST segment elevation. This is the first report providing direct evidence that reperfusion arrhythmias may be the cause of sudden death in individuals with anomalous coronary arteries.

Bundle branch reentrant ventricular tachycardia.

Bundle branch reentrant (BBR) tachycardia is an uncommon form of ventricular tachycardia (VT) incorporating both bundle branches into the reentry circuit. The arrhythmia is usually seen in patients with an acquired heart disease and significant conduction system impairment, although patients with structurally normal heart have been described. Surface ECG in sinus rhythm (SR) characteristically shows intraventricular conduction defects. Patients typically present with presyncope, syncope or sudden death because of VT with fast rates frequently above 200 beats per minute. The QRS morphology during VT is a typical bundle branch block pattern, usually left bundle branch block, and may be identical to that in SR. Prolonged His-ventricular (H-V) interval in SR is found in the majority of patients with BBR VT, although some patients may have the H-V interval within normal limits. The diagnosis of BBR VT is based on electrophysiological findings and pacing maneuvers that prove participation of the His- Purkinje system in the tachycardia mechanism. Radiofrequency catheter ablation of a bundle branch can cure BBR VT and is currently regarded as the first line therapy. The technique of choice is ablation of the right bundle. The reported incidence of clinically significant conduction system impairment requiring implantation of a permanent pacemaker varies from 0% to 30%. Long-term outcome depends on the underlying cardiac disease. Patients with poor systolic left ventricular function are at risk of sudden death or death from progressive heart failure despite successful BBR VT ablation and should be considered for an implantable cardiovertor-defibrillator.

Is there a need to remove an old pacemaker when implanting a new device in the contralateral side?

BACKGROUND: Device replacement or revision may constitute 25% of pacemaker procedures. In patients needing pacemaker system replacement the usual approach is from the ipsilateral side of the previous system. In cases where the contralateral side is used the previous pulse generator is removed. OBJECTIVE: To test the feasibility of implanting a new system in the contralateral side without the removal of the old system. METHODS: We present 10 patients, age range 30-88 years (median 73), with clinical indication of pacemaker replacement where the contralateral side was used. In eight patients the replacement was lead-related, and in the remaining two was due to other clinical indications. In all cases the ipsilateral approach was felt to be contraindicated because of local vein and/or pocket complications. Following the new pacemaker implantation the old system was reprogrammed at the lowest rate, lowest output and highest sensitivity. RESULTS: All patients underwent uneventful implantation. Post-surgery monitoring and Holter recordings failed to show any interference by the old system. CONCLUSIONS: In clinically indicated cases it is feasible to implant a new device in the contralateral side without removing the old pulse generator, thereby avoiding an additional surgical procedure and reducing periprocedural complications.

Paroxysmal atrioventricular block: clinical experience with 20 patients.

BACKGROUND: Paroxysmal atrioventricular (AV) block is an ill-defined entity, previously described in sporadic cases in association with vasovagal reaction, coronary angiography and distal conduction disease. METHODS: We describe 20 patients (10 women) aged 26 to 80 years with symptomatic paroxysmal AV block. RESULTS: Eight patients had ischemic heart disease-three with dilated cardiomyopathy, and two with co-existing carotid sinus hypersensitivity. Eight were taking chronic AV blockers. In five patients, the paroxysmal AV block occurred during a vagal reaction, in one during migranotic headaches, in one following aortic valve replacement and in one while recovering from acute myocardial infarction. The events lasted between 2.2 and 36 s. In 10 patients, the QRS configuration on the electrocardiogram was wide. Immediate treatment consisted of intravenous atropine and fluid supplements in two patients, discontinuation of the AV blocking agents in four, and the insertion of a temporary pacemaker in eight. Seventeen patients required a permanent pacemaker. CONCLUSIONS: Paroxysmal AV block is an underestimated clinical entity related to vagal reaction, AV blocking drugs and distal conduction disease. Most of our patients eventually required implantation of a permanent pacemaker.