Prevalence, predictors, and mortality significance of the causative arrhythmia in patients with electrical storm

INTRODUCTION: Electrical storm (ES) is characterized by either refractory ventricular tachycardia (VT) or ventricular fibrillation (VF). However, little is known about the prevalence, predictors, and mortality implications of the causative arrhythmia in ES. We sought to assess the prevalence, predictors, and survival significance of VT and VF as the causative arrhythmia of ES in implantable cardioverter defibrillator (ICD) patients. METHODS AND RESULTS: Consecutive patients from January 2000 to December 2002 who presented to the ICD clinic with > or = 2 separate ventricular arrhythmic episodes requiring shock within 24 hours were included in the study. ICD interrogation confirmed the number of shocks and provided electrograms for interpretation of the causative arrhythmia. Patients were grouped as VF or VT according to the causative arrhythmia. Their prevalence, predictors, and mortality rates were compared. Of 2,028 patients assessed in the ICD clinic, 208 (10%) presented with ES. VF was the cause of ES in 99 of 208 patients, for an overall prevalence of 48%. Original ICD indication, coronary artery disease, and amiodarone therapy were predictive for the causative arrhythmia. There was no mortality difference between the VT and VF groups; however, both groups had significantly increased mortality compared to a control ICD population without ES. CONCLUSION: VF is the causative arrhythmia for a sizable proportion of patients with ES. The initial ICD indication, coronary artery disease, and amiodarone therapy are predictors of the causative arrhythmias in ES. There does not appear to be any mortality difference between ES patients with VT and VF, but mortality is increased in patients with ES versus control ICD patients without ES.     

Clinical and demographic determinants of heart rate variability in patients post myocardial infarction: insights from the cardiac arrhythmia suppression trial (CAST)

BACKGROUND: Clinical and demographic determinants of heart rate variability (HRV), an almost universal predictor of increased mortality, have not been systematically investigated in patients post myocardial infarction (MI). HYPOTHESIS: The study was undertaken to evaluate the relationship between pretreatment clinical and demographic variables and HRV in the Cardiac Arrhythmia Suppression Trial (CAST). METHODS: CAST patients were post MI and had > or =6 ventricular premature complexes/h on pretreatment recording. Patients in this substudy (n = 769) had usable pretreatment and suppression tapes and were successfully randomized on the first antiarrhythmic treatment. Tapes were rescanned; only time domain HRV was reported because many tapes lacked the calibrated timing signal needed for accurate frequency domain analysis. Independent predictors of HRV were determined by stepwise selection. RESULTS: Coronary artery bypass graft surgery (CABG) after the qualifying MI was the strongest determinant of HRV. The markedly decreased HRV associated with CABG was not associated with increased mortality. Ejection fraction and diabetes were also independent predictors of HRV. Other predictors for some indices of HRV included beta-blocker use, gender, time from MI to Holter, history of CABG before the qualifying MI, and systolic blood pressure. Decreased HRV did not predict mortality for the entire group. For patients without CABG or diabetes, decreased standard deviation of all NN intervals (SDANN) predicted mortality. Clinical and demographic factors accounted for 31% of the variance in the average of normal-to-normal intervals (AVGNN) and 13-26% of the variance in other HRV indices. CONCLUSIONS: Heart rate variability post MI is largely independent of clinical and demographic factors. Antecedent CABG dramatically reduces HRV. Recognition of this is necessary to prevent misclassification of risk in patients post infarct.     

Avoiding interpretive pitfalls when assessing arrhythmia suppression after myocardial infarction: insights from the long-term observations of the placebo-treated patients in the Cardiac Arrhythmia Pilot Study (CAPS)

The Cardiac Arrhythmia Pilot Study (CAPS) was a 1 year trial that analyzed the safety and effectiveness of arrhythmia suppression in 502 patients surviving acute myocardial infarction who had greater than or equal to 10 ventricular premature depolarizations/h or greater than or equal to 5 runs of ventricular tachycardia on a Holter recording obtained 6 to 60 days after the acute infarction. Because 100 of these patients received placebo in a double-blind fashion for 1 year, a comprehensive objective analysis was performed of spontaneous arrhythmia changes based on real data rather than statistical estimates. In the CAPS placebo group, 19% developed some serious clinical event in 1 year (death, heart failure, proarrhythmia) that could likely be attributable to antiarrhythmic drug toxicity. A significant reduction in the frequency of ventricular premature depolarizations (p = 0.004) occurred in the first few weeks of "therapy" with a further significant (p less than 0.04) decrease between 3 to 12 months. After initiation of placebo antiarrhythmic therapy, 27% had "apparent ventricular premature depolarization suppression" (greater than or equal to 70% reduction) after one Holter recording evaluation and nearly half (48%) after six Holter recordings to assess suppression were performed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical risk predictors associated with cardiac mortality following vascular surgery in South African patients

Clinical risk prediction is important in the prognostication of peri-operative cardiac complications and the management of high-risk cardiac patients for major non-cardiac surgery. However, the current pre-operative clinical risk indices have been derived in European and American patients and not validated in South African patients. The purpose of this study was to evaluate the utility of the clinical risk predictors identified in Lee's revised cardiac risk index and in the African arm of the INTERHEART study, in predicting cardiac mortality following vascular surgery in South African patients. A retrospective cohort study was conducted of all patients undergoing elective or urgent vascular surgery at Inkosi Albert Luthuli Central Hospital over a three-year period. All in-hospital deaths were identified and classified into cardiac or non-cardiac deaths by an investigator blinded to the patients' pre-operative clinical risk predicators. A second investigator blinded to the cause of death identified the following clinical risk predictors: history of ischaemic heart disease, congestive cardiac failure and cerebrovascular accident, presence of diabetes, hypertension and obesity (BMI > 30 kg.m(-2)), elevated serum creatinine (> 180 micromol.l(-1)), positive smoking history and ethnicity. The main finding was that a serum creatinine level of greater than 180 micromol.l(-1) and a positive smoking history were significantly associated with cardiac death (p = 0.012, p = 0.012, respectively). Multivariate analyses using a backward stepwise modeling technique found only a serum creatinine of > 180 micromol.l(-1) and a positive smoking history to be significantly associated with cardiac mortality (p = 0.038, 0.035, respectively) with an odds ratio and 95% confidence interval of 3.02 (1.06-8.59) and 3.40 (1.09-10.62), respectively. All other clinical predictors were not significantly different between the two groups. However, based on the sample size of this study, a type 2 or b error may have resulted in the other risk predictors not being identified as important clinical predictors of cardiac mortality. Therefore, until such time as a study of adequate power is conducted, a history of ischaemic heart disease, congestive cardiac failure, diabetes and cerebrovascular accidents should still be considered to be important clinical risk predictors in South African surgical patients. In conclusion, an elevated serum creatinine and a positive history for smoking are important clinical predictors of cardiac mortality in South African patients following elective or urgent vascular surgery.     

Hereditary transthyretin amyloidosis: baseline characteristics of patients in the NEURO-TTR trial

Abstract

Background: Hereditary transthyretin (ATTRm) amyloidosis is a rare, progressive and fatal disease with a range of clinical manifestations.

Objective: This study comprehensively evaluates disease characteristics in a large, diverse cohort of patients with ATTRm amyloidosis.

Methods: Adult patients (N?=?172) with Stage 1 or Stage 2 ATTRm amyloidosis who had polyneuropathy were screened and enrolled across 24 investigative sites and 10 countries in the NEURO-TTR trial (www.clinicaltrials.gov, NCT01737398). Medical and disease history, quality of life, laboratory data, and clinical assessments were analyzed.

Results: The NEURO-TTR patient population was diverse in age, disease severity, TTR mutation, and organ involvement. Twenty-seven different TTR mutations were present, with Val30Met being the most common (52%). One third of patients reported early onset disease (before age 50) and the average duration of neuropathy symptoms was 5.3 years. Symptoms affected multiple organs and systems, with nearly 70% of patients exhibiting broad involvement of weakness, sensory loss, and autonomic disturbance. Over 60% of patients had cardiomyopathy, with highest prevalence in the United States (72%) and lowest in South America/Australasia (33%). Cardiac biomarker NT-proBNP correlated with left ventricular wall thickness (p<.001). Quality of life, measured by Norfolk QoL-DN and SF-36 patient-reported questionnaires, was significantly impaired and correlated with disease severity.

Conclusions: Baseline data from the NEURO-TTR trial demonstrates ATTRm amyloidosis as a systemic disease with deficits in multiple organs and body systems, leading to decreased quality of life. We report concomitant presentation of polyneuropathy and cardiomyopathy in most patients, and early involvement of multiple body systems.     

Nosocomial bacteremia in very old patients: predictors of mortality

BACKGROUND AND AIMS: Nosocomial Bacteremia (NB) is associated with high mortality in elderly patients. To determine specific prognostic factors for 7- and 30-day mortality in elderly patients with NB, we analysed the characteristics of 62 NB patients, retrospectively. METHODS: This retrospective study concerns 62 cases of NB diagnosed within a 3-year period in a geriatric department. Bacteremia is described according to CDC definitions. Epidemiological characteristics, co-morbidities, clinical (activities of daily living (ADL) before NB) and biological findings (neutrophil count, lymphocyte count, albuminemia before NB) were collected for each patient. A systemic clinical reaction was defined by the presence of one of the following parameters: chills, hypothermia <36 degrees C or hyperthermia >38.5 degrees C, or shock. Types of micro-organism and source of NB were also collected. All variables were analysed for mortality at day 7 (7-day mortality) and at day 30 (30-day mortality). RESULTS: The 7-day mortality rate was 21% and the 30-day rate was 45%. In multivariate analysis, 7-day mortality was only associated with the absence of systemic clinical reaction [OR 9.7 (3.7-25.7)]. Again, in multivariate analysis, 30-day mortality was associated with an ADL score <2 [OR 8.3 (4.3-16.4)] and cocci gram positive NB [OR= 3.6 (1.9-6.9)]. CONCLUSIONS: The absence of any systemic clinical reaction as a single independent predictor for 7-day mortality suggests either a poorer immune response to nosocomial bacteremia or a delay in diagnosis. Functional status was the strongest predictor for 30-day mortality. In this population, further prospective studies need to include these factors to evaluate predictors of mortality for serious infectious diseases.     

Use of rhythmol in patients with cardiac arrhythmia

Twenty-six patients were treated with Rhythmol (Ro 2-5803) during 29 episodes of arrhythmia. The drug was given orally and intravenously. The criterion of effectiveness was conversion to normal sinus rhythm.

Restoration of sinus rhythm occurred in seven episodes of arrhythmia, six of these being acute arrhythmias. The seventh was chronic atrial arrhythmia. Only one of 15 episodes of chronic atrial arrhythmias was converted to sinus rhythm.

Side effects were hypotension in 3 of 17 intravenous trials; gastrointestinal symptoms in 9 of 16 oral trials; and widening of the QRS complex of the electrocardiogram in 4 trials (three oral and one intravenous).

In its present form, this drug has no advantages over the usual agents for the treatment of chronic atrial arrhythmias. Its use by mouth is associated with a forbidding incidence of gastrointestinal reactions.     

Implantable cardioverter-defibrillators in elderly patients: outcome and predictors of mortality

Journal of Interventional Cardiac Electrophysiology - The implantable cardioverter-defibrillator (ICD) is the therapy of choice for the prevention of sudden cardiac death. The number of elderly...     

Risk of mortality for ventricular arrhythmia in ambulatory LVAD patients

Risk of Mortality for Ventricular Arrhythmia . Background: There are limited data regarding the incidence and prognostic significance of ventricular arrhythmias (VA) in ambulatory continuous flow left ventricular assist device (LVAD) patients. Methods: Sixty‐one consecutive patients from November 1, 2006 through December 31, 2010 with an LVAD and implantable cardioverter defibrillator that survived to discharge from the LVAD implantation admission were studied. Follow‐up began from date of discharge with both devices in situ and ended with death, transplant, on June 1, 2011. Pre‐LVAD VA history was related to the primary endpoints of post‐LVAD VA, mortality, and the combined endpoint of post‐LVAD VA/mortality. Results: During a mean follow‐up of 622 days 19 patients (31%) experienced VA (14 episodes of VT, 5 episodes of VF). Pre‐LVAD VA was predictive of post‐LVAD VA (hazard ratio [HR] 2.91, P = 0.026) and the combined post‐LVAD VA/mortality endpoint (HR 2.70, P = 0.021) but only displayed a nonsignificant association with mortality (HR 2.30, P = 0.11). In multivariate analysis, pre‐LVAD VA remained a significant predictor of post‐LVAD VA (HR 2.84, P = 0.03) and the combined post‐LVAD VA/mortality endpoint (HR 2.65, P = 0.025). Post‐LVAD VA was the strongest univariate predictor of mortality (HR 13.92, P < 0.001) and remained so after multivariate adjustment (HR 9.69, P = 0.001). Post‐LVAD VA occurred at a mean of 1 year from mortality events with 45% within 1 month. Conclusions: Pre‐LVAD VA is a significant predictor of post‐LVAD VA but not of mortality. VA in the continuous flow LVAD population carries a significant risk of mortality often within the first month. (J Cardiovasc Electrophysiol, Vol. 23, pp. 515‐520, May 2012)     

Frequency and predictors of return to incentive spirometry volume baseline after cardiac surgery

Incentive spirometry (IS) is routinely used in most clinical settings, but evaluation of patient efficacy of IS is not standardized. The purpose of this study was to describe the degree and predictors of return to preoperative IS volume after cardiac surgery. IS volumes were documented in 69 subjects (71% men; mean age, 59 years) undergoing cardiac surgery during the preoperative evaluation and twice daily postoperatively. Nineteen percent of subjects achieved their IS preoperative volume by hospital discharge. Based on highest volume achieved, subjects achieved an average of 75% of their preoperative volume by discharge, and only age and number of bypass grafts predicted return to preoperative IS volume. These data may assist nurses and patients to set realistic goals for postoperative IS volume achievement.     

老年肺炎患者并发心律失常的危险因素分析

目的探讨老年肺炎住院患者心律失常的发生情况及其危险因素,以期为老年肺炎患者发生心律失常的合理防治提供依据。方法回顾性分析238例老年肺炎住院患者的临床资料,采用多因素Logistic回归分析方法对64例并发心律失常患者(观察组)与174例未并发心律失常患者(对照组)进行比较分析。结果多因素Logistic逐步回归分析显示:年龄(OR=1.395,95%CI为1.005~1.935)、心血管病(OR=2.510,95%CI为1.179~5.354)、低氧血症(OR=2.499,95%CI为1.153~5.418)、酸中毒(OR=2.869,95%CI为1.175~7.005)、中~重度贫血(OR=3.397,95%CI为1.277~9.036)、电解质紊乱(OR=3.628,95%CI为1.292~9.374)、低射血分数(OR=5.140,95%CI为1.924~13.731)、机械通气(OR=5.433,95%CI为2.031~14.562)与老年肺炎患者并发心律失常有相关性。结论肺炎并发心律失常的危险因素有年龄、心血管疾病史、低氧血症、酸中毒、贫血、电解质紊乱、低射血分数以及机械通气。加强老年肺炎患者心律失常的监控,重视危险因素,早期预防和治疗,可提高患者生活质量。     

Clinical predictors of arrhythmia inducibility in survivors of cardiac arrest: importance of gender and prior myocardial infarction

Clinical characteristics that correlate with arrhythmia inducibility were determined in 150 consecutive survivors of cardiac arrest. All underwent electrophysiologic study with a uniform protocol when they were not receiving antiarrhythmic drugs. A ventricular tachyarrhythmia (sustained monomorphic ventricular tachycardia, ventricular fibrillation or nonsustained ventricular tachycardia) was induced in 113 patients (75%). The strongest correlates of inducing a tachyarrhythmia were male gender (p less than 0.0001) and a history of prior myocardial infarction (p less than 0.0001). Induction of sustained monomorphic tachycardia alone was also strongly related to gender and prior infarction; in particular, none of 26 women without prior infarction had induction of sustained monomorphic ventricular tachycardia. Among patients with induced sustained tachyarrhythmias, those with induced monomorphic ventricular tachycardia were distinguished from those with induced ventricular fibrillation in they were more likely to have coronary artery disease (p = 0.0001), healed myocardial infarction (p = 0.0002), left ventricular aneurysm (p = 0.0007) and ventricular tachycardia documented at the time of cardiac arrest (p = 0.02). Other variables showing significant correlations with arrhythmia inducibility were ejection fraction, documentation of ventricular tachycardia at the time of cardiac arrest and presence of an intraventricular conduction delay. However, stepwise logistic regression identified male gender and healed myocardial infarction as the only independent predictors of arrhythmia inducibility. On the basis of these two variables alone, arrhythmia inducibility or noninducibility could be correctly predicted in 89% of the patients in this series.