[Show abstract][Hide abstract] ABSTRACT: The PROSPECT trial reported no single echocardiographic measurement of dyssynchrony is recommended to improve patient selection for cardiac resynchronization therapy (CRT).
In 100 consecutive patients who received CRT, we analyzed 27 ECG and echocardiographic variables to predict a positive response to CRT defined as a left ventricular (LV) end systolic volume decrease of ≥ 15% after CRT.
Right ventricular (RV) pacing-induced left bundle branch block (LBBB), time difference between LV ejection measured by tissue Doppler and pulsed wave Doppler (T(TDI-PW)), and wall motion score index (WMSI) were significantly associated with positive CRT response by multivariate regression. We assigned 1 point for RV pacing-induced LBBB, 1 point for WMSI ≤ 1.59, and 2 points for T(TDI-PW) > 50 ms. Overall mean response score was 1.79 ±1.39. Cutoff point for response score to predict positive response to CRT was > 2 by receiver operating characteristic (ROC) analysis. Area under ROC curve was 0.97 (p = 0.0001). Cardiac resynchronization therapy responders in patients with response score > 2 and ≤ 2 were 36/38 (95%) and 7/62 (11%, p < 0.001), respectively. After age and gender adjustment, the response score was related to CRT response (OR = 45.4, p < 0.0001).
A response score generated from clinical, ECG and echocardiographic variables may be a useful predictor for CRT response. However, this needs to be validated.
[Show abstract][Hide abstract] ABSTRACT: We investigated in 136 consecutive patients with heart failure receiving cardiac resynchronization therapy (CRT) the effect of carvedilol versus metoprolol CR/XL versus no beta blocker on mortality. Of the 136 patients, 42 (31%) were on carvedilol, 80 (59%) were on metoprolol CR/XL, and 14 (10%) were not on a beta blocker. A decrease of left ventricular end-systolic volume ≥15% after CRT was defined as a positive response to CRT. Of the 136 patients, 62 (46%) responded to CRT. It was found that both carvedilol and metoprolol CR/XL were not related to CRT response on using Cox univariate regression analysis. Twenty-two of the 136 patients (16%) died during follow-up of 17 ± 10 months after initiating CRT. Mortality occurred in 14 of 80 patients (18%) on metoprolol CR/XL, in 3 of 42 patients (7%) on carvedilol, and in 5 of 14 patients (36%) not on beta blockers (P = 0.04). After adjustment for age, gender, and the variables with significant differences by Cox univariate regression, both carvedilol (hazard ratio = 0.14; P = 0.03; 95% confidence interval = 0.02-0.86) and metoprolol CR/XL (hazard ratio = 0.19; P = 0.02; 95% confidence interval = 0.04-0.80) were found to be related to mortality by Cox multivariate regression.
No preview · Article · Jun 2011 · American journal of therapeutics
[Show abstract][Hide abstract] ABSTRACT: We hypothesized a patient selection score (PSS) may improve patient selection for cardiac resynchronization therapy (CRT).
Of 136 patients who received CRT, group A included 100 study patients and group B 36 patients for validation. A positive response to CRT was a left ventricular (LV) end-systolic volume decrease of ≥15% and survival from heart failure at end of follow-up.
Of 100 group A patients, 37 (37%) were CRT responders during 14-month follow-up. A 7-point PSS was generated based on six variables. The cutoff point for PSS to predict a positive response to CRT was >4 by receiver operating characteristic (ROC) analysis. The area under the ROC curve (AUC) for PSS to predict CRT response was 0.94 (P = 0.0001). CRT responders in patients with a PSS > 4 and ≤4 were 33/40 (83%), and 4/60 (7%), respectively (P < 0.001). Multivariate Cox proportional regression analysis showed that PSS was related to CRT response (hazard ratio = 10.3, P < 0.0001). The CRT response rate in patients with a PSS > 4 in Group B was also significantly higher compared to a PSS ≤ 4 (88% vs. 16%, P < 0.001). The AUC for PSS to predict a CRT response in Group B was 0.91 (P = 0.0001).
Patients with a PSS >4 are the most likely to respond to CRT. Using this score system, a PSS score >4 can predict the probability of a CRT response up to 88% in patients with heart failure and a wide QRS duration.
No preview · Article · Feb 2011 · Echocardiography
[Show abstract][Hide abstract] ABSTRACT: Background. Due to underrepresentation of patients with chronic kidney disease (CKD) in large Implantable-Cardioverter Defibrillator (ICD) clinical trials, the impact of ICD remains uncertain in this population.
Methods. Consecutive patients who received ICD at Creighton university medical center between years 2000–2004 were included in a retrospective cohort after excluding those on maintenance dialysis. Based on baseline Glomerular filtration rate (GFR), patients were classified as severe CKD: GFR < 30 mL/min; moderate CKD: GFR: 30–59 mL/min; and mild or no CKD: GFR ≥ 60 mL/min. The impact of GFR on appropriate shocks and survival was assessed using Kaplan-Meier method and Generalized Linear Models (GLM) with log-link function.
Results. There were 509 patients with a mean follow-up of 3.0 + 1.3 years. Mortality risk was inversely proportional to the estimated GFR: 2 fold higher risk with GFR between 30–59 mL/min and 5 fold higher risk with GFR < 30 mL/min. One hundred and seventy-seven patients received appropriate shock(s); appropriate shock-free survival was lower in patients with severe CKD (GFR < 30) compared to mild or no CKD group (2.8 versus 4.2 yrs). Conclusion. Even moderate renal dysfunction increases all cause mortality in CKD patients with ICD. Severe but not moderate CKD is an independent predictor for time to first appropriate shock.
Full-text · Article · Dec 2010 · Cardiology Research and Practice
[Show abstract][Hide abstract] ABSTRACT: The combination of pulsed wave (PW) and tissue Doppler imaging (TDI) has been proposed as a new method to assess left ventricular (LV) mechanical dyssynchrony (LVMD), but results have not been validated. We investigated the correlation of a combination of PW and TDI with a positive response to cardiac resynchronization therapy (CRT).
We studied 108 consecutive patients who received CRT. Patients with atrial fibrillation were excluded. The time difference (T(PW-TDI)) between onset of QRS to the end of LV ejection by PW (T(PW)) and onset of QRS to the end of the systolic wave in LV basal segments with greatest delay by TDI (T(TDI)) was measured before CRT and during short-term and long-term follow-up.
The T(PW-TDI) interval before CRT was 74 ±48 ms. Intra-observer variabilities for T(PW) and T(TDI) were 1.5 ±0.24% and 1 ±0.17%. Inter-observer variabilities for T(PW) and T(TDI) were 1 ±0.36% and 1 ±0.64%, respectively. T(PW-TDI) > 50 ms was defined as the cutoff value for diagnosis of LVMD by receiver operating curve (ROC) analysis. During follow-up of 15 ±11 months, the sensitivity and specificity of TP(PW-TDI) to predict a positive response to CRT were 98% and 82%, respectively. The area under the ROC curve was 0.92. There was a significant agreement between LVMD determined by T(PW-TDI) and the positive response to CRT (κ=0.80).
Left vertricular dyssynchrony detected by the method combining PW and TDI demonstrated a high reproducibility, sensitivity, specificity and agreement with a positive response to CRT.
[Show abstract][Hide abstract] ABSTRACT: Lead perforation is a major complication of cardiac rhythm management devices (CRMD), occurring in about 1%. While most lead perforations occur early, numerous instances of delayed lead perforation (occurring >30 days after implantation) have been reported in the last few years. Only about 40 such cases have been published, with the majority occurring <1 year after implantation. Herein, we describe the case of an 84-year-old female who presented with recurrent syncope and was diagnosed to have delayed pacemaker lead perforation 4.8 years after implantation. Through this report, we intend to highlight the increasing use of CRMD in elderly patients, and the lifelong risk of complications with these devices. Presentation can be atypical and a high index of suspicion is necessary for diagnosis.
Preview · Article · Jul 2010 · Cardiology Research and Practice
[Show abstract][Hide abstract] ABSTRACT: Background: We hypothesized that segmental wall motion abnormalities (WMAs) are related to cardiac resynchronization therapy (CRT) response. Methods: We studied 108 patients who received CRT, 69 with ischemic and 39 with nonischemic heart disease. A wall motion score index (WMSI) was analyzed using a 17-segment model and calculated by the total score/number of segments analyzed. A decrease of left ventricular end systolic volume ≥15% after CRT was defined as a positive response to CRT. Results: Of 108 patients, 1,054/1,836 segments (57%) had WMAs. The mean WMSI was 2.06 in patients with ischemic heart disease and 1.04 in patients with nonischemic heart disease (P < 0.0001). The area under the receiver operating characteristic curve for a WMSI predicting a positive response to CRT was 0.70 (P = 0.0001). The cutoff point was a WMSI ≤2 for prediction of a positive response to CRT. After adjustment for age, gender, and clinical features, the WMSI persistently related to CRT responders (P = 0.01). During 15-month follow-up, the percentage of CRT nonresponders in patients with a WMSI >2 was significantly higher (82%) compared to patients with a WMSI ≤2 (47%, P = 0.005) and nonischemic heart disease (36%, P < 0.001). In 59 patients with left ventricular mechanical dyssynchrony, the percentage of negative responders to CRT in patients with a WMSI >2, ≤2, and nonischemic heart disease were 53% (8 of 15), 16% (3 of 19) and 0% (0 of 25), respectively (P < 0.001). Conclusions: A large extent of WMAs and a WMSI >2 predicted a poorer CRT response. (ECHOCARDIOGRAPHY, Volume 26, November 2009)
No preview · Article · Oct 2009 · Echocardiography
[Show abstract][Hide abstract] ABSTRACT: We studied 99 consecutive patients with class III-IV systolic heart failure with a left ventricular ejection fraction (LVEF) < or =35% and a QRS duration <120 milliseconds. Patients with cardiac resynchronization therapy were excluded. Echocardiography was performed in all patients before and after optimal standard heart failure therapy. The septal-to-posterior wall motion delay (SPWMD) > or =130 milliseconds on echocardiogram was defined as left ventricular mechanical dyssynchrony (LVMD). Sixty-nine of 99 patients (70%) had ischemic heart disease. During follow-up of 15.2 +/- 9.8 months, LVEF improvement > or =15% was greater patients in nonischemic group (50%, 15/30) than in ischemic group (9%, 6/69; P < 0.001). After adjustment for age, gender, and clinical and echocardiographic characteristics, ischemic heart disease and grade of coronary disease were persistently related to LVEF improvement > or =15% (P = 0.03 and 0.02, respectively). Twenty of 99 patients (20%) had SPWMD > or =130 milliseconds (LVMD group), and 79 of 99 patients (80%) had SPWMD <130 milliseconds (non-LVMD group). LVEF increased in both groups (P = 0.005) during follow-up, but the percentage of patients with LVEF improvement > or =15% in LVMD was greater compared with patients without LVMD (40% versus 16%, respectively, P = 0.03). In conclusion, the improvement of LVEF in patients with systolic heart failure and narrow QRS was greater in patients with nonischemic heart disease and LVMD compared with patients with ischemic heart disease and absence of LVMD during medical therapy without cardiac resynchronization therapy.
No preview · Article · Feb 2009 · American journal of therapeutics
[Show abstract][Hide abstract] ABSTRACT: Hydroxymethylglutaryl coenzyme A inhibitors (statins) reduce mortality in coronary artery disease, heart failure and have been shown to have pleiotropic anti-arrhythmic effects. We performed a meta-analysis to assess the utility of statins in atrial fibrillation (AF) and ventricular tachyarrhythmia (VA). Systematic review of all studies from 1990 until 2006 identified fourteen good quality studies on statins and AF and five studies on statins and VA. Meta-analysis was performed using the random-effects model and the pooled risk ratio (RR) for AF was RR: 0.73 (95% CI: 0.62-0.86) and for long term VA was 0.64 (95% CI: 0.44-0.94). In the subgroup analysis that included only randomized studies, the pooled risk ratio (RR) using random effects model for AF was RR: 0.64 (95% CI: 0.37-1.14). In conclusion, statins decrease the incidence and recurrence of AF and VA, but additional randomized studies are required to confirm this pleiotropic effect of statins.
No preview · Article · Jan 2009 · Internet Journal of Cardiology
[Show abstract][Hide abstract] ABSTRACT: Background: Amiodarone is an effective antiarrhythmic agent with a substantial risk of toxicity. Monitoring is recommended with the following minimum: 2 clinic visits per year including thyroid function tests (TFTs) and liver function tests (LFTs), annual eye exam (AEE) and chest x-ray (CXR).
PURPOSE: The objective of this study was to evaluate adherence to the minimum monitoring standards for amiodarone in two cohorts of patients (one treated between 1988-1992 and the other 2000-2004). Adherence to monitoring was correlated with adverse drug reactions and outcome of therapy.
METHODS: Consecutive patients initiated on amiodarone during 1988-1992 and 2000-2004 were followed prospectively. Only patients remaining on amiodarone for ≥ 12 mos were included. Patients with a minimum of 2 clinic visits having TFTs and LFTs, AEE and CXR were considered to be adherent to monitoring. Outcomes were categorized as (1) discontinued for lack of efficacy (DC-LOE); (2) discontinued due to SE (DC-SE); (3) continued with SE (C-SE); and (4) continued without SE (C-NoSE).
RESULTS: 577 patients initiated on amiodarone during 1988-1992 and 553 during 2000-2004 were included. Mean follow-up was 22 months. Outcomes for all 1130 patients include: DC-LOE 18%; DC-AE 38%; C-NoAE 22%; and C-AE 22%. The proportion of patients compliant with follow-up was significantly greater in 1988-1992 (67%) compared to 2000-2004 (55%; p < 0.05). Patients with the outcome of DC-AE were significantly more likely to be non-compliant with follow-up in both time periods (p < 0.05). The most common types of side effects in the DC-AE groups were pulmonary, hyperthyroidism, neurologic (tremor), and hepatic.
Conclusion: Patients compliant with follow-up are less likely to discontinue amiodarone due to side effects than non-compliant patients. It is hypothesized that compliant patients have side effects that can be managed clinically which reduces the severity of side effects and reduces the number requiring drug discontinuation.
[Show abstract][Hide abstract] ABSTRACT: Delayed intracardiac lead perforation has been defined as migration and perforation after one month of implantation. It is a rare complication; pathophysiology and optimal management are currently unclear. Recognition of these cases becomes important with increasing use of these devices. We describe such a case of delayed lead perforation.
Full-text · Article · Feb 2008 · Pacing and Clinical Electrophysiology
[Show abstract][Hide abstract] ABSTRACT: This study investigated the circadian, daily, and seasonal distributions of ventricular arrhythmias in patients with new implantable cardioverter-defibrillator placement at Creighton University Medical Center from January 2000 to December 2004. The incidence and distribution of ventricular tachyarrhythmias as recorded by implantable cardioverter-defibrillators were analyzed with respect to season, month, day of the week, and average daily temperature. Data from 154 consecutive patients (mean age 67 +/- 14 years; 78% men, 71% with ischemic heart disease [IHD], mean left ventricular ejection fraction 34 +/- 15%) were analyzed. During a mean follow-up of 35 +/- 19 months, a total of 1,055 episodes of spontaneously terminated ventricular tachycardia (VT) and 612 episodes of VT or ventricular fibrillation with appropriate device therapy occurred. Distributions in the incidence of VT and VT or ventricular fibrillation receiving appropriate therapy were similar in patients with IHD and non-IHD. Spontaneously terminated VT and appropriately treated VT or ventricular fibrillation episodes occurred with the greatest incidence in the winter months and the lowest incidence in summer, spring, and fall. A linear regression between the number of episodes and the average daily temperature showed a greater likelihood of the 2 events occurring on cooler days, irrespective of the cause of cardiac disease. A weekly distribution was also observed, with the greatest proportion of episodes occurring on Fridays and the lowest on Saturdays and Sundays. A bimodal circadian distribution was present, with the greatest peak occurring from 8 a.m. to 1 p.m. and a smaller peak occurring from 5 p.m. to 10 p.m. In conclusion, the occurrence of ventricular tachyarrhythmias appears to follow circadian, daily, and seasonal distributions that are similar in patients with IHD and non-IHD. The incidence inversely correlates with average daily temperatures.
No preview · Article · Nov 2007 · The American Journal of Cardiology
[Show abstract][Hide abstract] ABSTRACT: Warfarin anticoagulation significantly reduces the risk of thromboembolism in patients with atrial fibrillation (AF). However, there are many patients with AF who begin anticoagulation only after left atrial thrombus (LAT) is detected by transesophageal echocardiography (TEE). The impact of anticoagulation in these patients has not been clearly described. The purpose of this study was to investigate the incidence of cerebrovascular accident (CVA) among AF patients who began warfarin before LAT was detected by TEE compared to those who began warfarin only after TEE demonstrated LAT and those did not receive warfarin at any point.
Of the 90 consecutive AF patients with LAT (male 48, female 42, age 71.5 +/- 10.1 years), 49 began warfarin more than 3 weeks before TEE (Group I); 29 began warfarin after TEE (Group II); and 12 did not receive warfarin at all (Group III).
The incidence of CVA in Group I (14%, 7/49, prior CVA 5, new CVA after TEE 2) was significantly lower than Group II (45%, 13/29, prior CVA 10, new CVA after TEE 3, P = 0.006) and III (42%, 5/12, prior CVA 3, new CVA after TEE 2, P = 0.047). Patients with persistent LAT had significantly higher incidence (64% vs 23%, P = 0.024) of CVA and lower CVA free survival than those with resolved LAT.
The incidence of CVA among AF patients, who began warfarin before LAT detection, is significantly lower than those who began warfarin after LAT detection as well as those who did not receive warfarin at all.
No preview · Article · Feb 2007 · Echocardiography