scholarly journals Microvolt T-Wave Alternans Is Modulated by Acute Low-Level Tragus Stimulation in Patients With Ischemic Cardiomyopathy and Heart Failure

2021 ◽  
Vol 12 ◽  
Author(s):  
Kanchan Kulkarni ◽  
Stavros Stavrakis ◽  
Khaled Elkholey ◽  
Jagmeet P. Singh ◽  
Kimberly A. Parks ◽  
...  

Aims: Microvolt T-wave alternans (TWA), an oscillation in T-wave morphology of the electrocardiogram (ECG), has been associated with increased susceptibility to ventricular tachy-arrhythmias, while vagus nerve stimulation has shown promising anti-arrhythmic effects in in vivo and ex vivo animal studies. We aimed to examine the effect of non-invasive, acute low-level tragus stimulation (LLTS) on TWA in patients with ischemic cardiomyopathy and heart failure.Methods: 26 patients with ischemic cardiomyopathy (left ventricular ejection fraction <35%) and chronic stable heart failure, previously implanted with an automatic implantable cardioverter defibrillator (ICD) device with an atrial lead (dual chamber ICD or cardiac resynchronization therapy defibrillator), were enrolled in the study. Each patient sequentially received, (1) Sham LLTS (electrode on tragus, but no stimulation delivered) for 5 min; (2) Active LLTS at two different frequencies (5 and 20 Hz, 15 min each); and (3) Active LLTS, during concomitant atrial pacing at 100 bpm at two different frequencies (5 and 20 Hz, 15 min each). LLTS was delivered through a transcutaneous electrical nerve stimulation device (pulse width 200 μs, frequency 5/20 Hz, amplitude 1 mA lower than the discomfort threshold). TWA burden was assessed using continuous ECG monitoring during sham and active LLTS in sinus rhythm, as well as during atrial pacing.Results: Right atrial pacing at 100 bpm led to significantly heightened TWA burden compared to sinus rhythm, with or without LLTS. Acute LLTS at both 5 and 20 Hz, during sinus rhythm led to a significant rise in TWA burden in the precordial leads (p < 0.05).Conclusion: Acute LLTS results in a heart-rate dependent increase in TWA burden.

2008 ◽  
Vol 24 (4) ◽  
pp. 224-227
Author(s):  
Kotaro Miyaji ◽  
Keisuke Abe ◽  
Koji Abe ◽  
Naomichi Kondo ◽  
Hiroki Suzuki ◽  
...  

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
H.Y Chang ◽  
W.R Chiou ◽  
P.L Lin ◽  
C.Y Hsu ◽  
C.T Liao ◽  
...  

Abstract Background Ischemic cardiomyopathy (ICM) has been associated with increased mortality when compared with non-ischemic cardiomyopathy (NICM) from several heart failure (HF) cohorts. Instead, PARADIGM study demonstrated similar event rates of cardiovascular (CV) death, all-cause mortality and HF readmissions between ICM and NICM patients. Although the beneficiary effect of sacubitril/valsartan (SAC/VAL) compared to enalapril on these endpoints was consistent across etiologic categories, PARADIGM study did not analyze the effect of ventricular remodeling of SAC/VAL on patients with different HF etiologies, which may significantly affect treatment outcomes. Purpose We aim to compare alterations of left ventricular ejection fraction (LVEF) following SAC/VAL treatment and its association with clinical outcomes in patients with different HF etiologies. Methods Treatment with angiotensin receptor neprilysin inhibitor for Taiwan heart failure patients (TAROT-HF) study is a multicenter study which enrolled 1552 patients with LVEF <40%, whom had been on SAC/VAL treatment from 9 hospitals between 2017 and 2018. After excluding patients without having follow-up echocardiographic studies, patients were grouped by HF etiologies and by LVEF changes following treatment for 8-month period. LVEF improvement ≥15% was defined as “significant improvement”, 5–15% as “marginal improvement”, and <5% or worse as “lack of improvement”. The primary endpoint was a composite of CV death or a first hospitalization for HF. Mean follow-up period was 726 days. Results A total of 1230 patients were analyzed. Patients with ICM were significantly older, more male, and prone to have associated hypertension and diabetes. On the other hand, patients with NICM had lower LVEF and higher likelihood of atrial fibrillation. LVEF increase was significantly greater in patients with NICM compared to those with ICM (11.2±12.4% vs. 6.9±9.8, p<0.001). The effect of ventricular remodeling of SAC/VAL on patients with NICM showed twin peaks diversity (Significant improvement 37.1%, lack of improvement 42.3%), whereas in patients with ICM the proportions of significant, marginal and lack of improvement groups were 19.4%, 28.2% and 52.4%, respectively. The primary endpoint showed twin peaks diversity also in patients with NICM in line with LVEF changes: adjusted HR for patients with NICM and significant improvement was 0.41 (95% CI 0.29–0.57, p<0.001), for patients with NICM and lack of improvement was 1.54 (95% CI 1.22–1.94, p<0.001). Analyses for CV death, all-cause mortality, and HF readmission demonstrated consistent results. Conclusion Patients with NICM had higher degree of LVEF improvement than those with ICM following SAC/VAL treatment, and significant improvement of LVEF in NICM patients may indicate favorable outcome. NICM patients without response to SAC/VAL treatment should serve as an indicator for poor clinical outcome and warranted meticulous HF management. Funding Acknowledgement Type of funding source: Private hospital(s). Main funding source(s): Cheng Hsin General Hospital


2020 ◽  
Vol 9 (17) ◽  
Author(s):  
Daniel N. Silverman ◽  
Mehdi Rambod ◽  
Daniel L. Lustgarten ◽  
Robert Lobel ◽  
Martin M. LeWinter ◽  
...  

Background Increases in heart rate are thought to result in incomplete left ventricular (LV) relaxation and elevated filling pressures in patients with heart failure with preserved ejection fraction (HFpEF). Experimental studies in isolated human myocardium have suggested that incomplete relaxation is a result of cellular Ca 2+ overload caused by increased myocardial Na + levels. We tested these heart rate paradigms in patients with HFpEF and referent controls without hypertension. Methods and Results In 22 fully sedated and instrumented patients (12 controls and 10 patients with HFpEF) in sinus rhythm with a preserved ejection fraction (≥50%) we assessed left‐sided filling pressures and volumes in sinus rhythm and with atrial pacing (95 beats per minute and 125 beats per minute) before atrial fibrillation ablation. Coronary sinus blood samples and flow measurements were also obtained. Seven women and 15 men were studied (aged 59±10 years, ejection fraction 61%±4%). Patients with HFpEF had a history of hypertension, dyspnea on exertion, concentric LV remodeling and a dilated left atrium, whereas controls did not. Pacing at 125 beats per minute lowered the mean LV end‐diastolic pressure in both groups (controls −4.3±4.1 mm Hg versus patients with HFpEF −8.5±6.0 mm Hg, P =0.08). Pacing also reduced LV end‐diastolic volumes. The volume loss was about twice as much in the HFpEF group (controls −15%±14% versus patients with HFpEF −32%±11%, P =0.009). Coronary venous [Ca 2+ ] increased after pacing at 125 beats per minute in patients with HFpEF but not in controls. [Na + ] did not change. Conclusions Higher resting heart rates are associated with lower filling pressures in patients with and without HFpEF. Incomplete relaxation and LV filling at high heart rates lead to a reduction in LV volumes that is more pronounced in patients with HFpEF and may be associated with myocardial Ca 2+ retention.


2005 ◽  
Vol 289 (4) ◽  
pp. H1729-H1735 ◽  
Author(s):  
Sophie Motte ◽  
Myrielle Mathieu ◽  
Serge Brimioulle ◽  
Anne Pensis ◽  
Lynn Ray ◽  
...  

Heart failure is associated with autonomic imbalance, and this can be evaluated by a spectral analysis of heart rate variability. However, the time course of low-frequency (LF) and high-frequency (HF) heart rate variability changes, and their functional correlates during progression of the disease are not exactly known. Progressive heart failure was induced in 16 beagle dogs over a 7-wk period by rapid ventricular pacing. Spectral analysis of heart rate variability and respiration, echocardiography, hemodynamic measurements, plasma atrial natriuretic factor, and norepinephrine was obtained at baseline and every week, 30 min after pacing interruption. Progressive heart failure increased heart rate (from 91 ± 4 to 136 ± 5 beats/min; P < 0.001) and decreased absolute and normalized (percentage of total power) HF variability from week 1 and 2, respectively ( P < 0.01). Absolute LF variability did not change during the study until it disappeared in two dogs at week 7 ( P < 0.05). Normalized LF variability increased in moderate heart failure ( P < 0.01), leading to an increased LF-to-HF ratio ( P < 0.05), but decreased in severe heart failure ( P < 0.044; week 7 vs. week 5). Stepwise regression analysis revealed that among heart rate variables, absolute HF variability was closely associated with wedge pressure, right atrial and pulmonary arterial pressure, left ventricular ejection fraction and volume, ratio of maximal velocity of early (E) and atrial (A) mitral flow waves, left atrial diameter, plasma norepinephrine, and atrial natriuretic peptide (0.45 < r < 0.65, all P < 0.001). In tachycardia-induced heart failure, absolute HF heart rate variability is a more reliable indicator of cardiac dysfunction and neurohumoral activation than LF heart rate variability.


2021 ◽  
Vol 10 (21) ◽  
pp. 4989
Author(s):  
Mohammad Abumayyaleh ◽  
Christina Pilsinger ◽  
Ibrahim El-Battrawy ◽  
Marvin Kummer ◽  
Jürgen Kuschyk ◽  
...  

Background: The angiotensin receptor-neprilysin inhibitor (ARNI) decreases cardiovascular mortality in patients with chronic heart failure with a reduced ejection fraction (HFrEF). Data regarding the impact of ARNI on the outcome in HFrEF patients according to heart failure etiology are limited. Methods and results: One hundred twenty-one consecutive patients with HFrEF from the years 2016 to 2017 were included at the Medical Centre Mannheim Heidelberg University and treated with ARNI according to the current guidelines. Left ventricular ejection fraction (LVEF) was numerically improved during the treatment with ARNI in both patient groups, that with ischemic cardiomyopathy (n = 61) (ICMP), and that with non-ischemic cardiomyopathy (n = 60) (NICMP); p = 0.25. Consistent with this data, the NT-proBNP decreased in both groups, more commonly in the NICMP patient group. In addition, the glomerular filtration rate (GFR) and creatinine changed before and after the treatment with ARNI in both groups. In a one-year follow-up, the rate of ventricular tachyarrhythmias (ventricular tachycardia and ventricular fibrillation) tended to be higher in the ICMP group compared with the NICMP group (ICMP 38.71% vs. NICMP 17.24%; p = 0.07). The rate of one-year all-cause mortality was similar in both groups (ICMP 6.5% vs. NICMP 6.6%; log-rank = 0.9947). Conclusions: This study shows that, although the treatment with ARNI improves the LVEF in ICMP and NICMP patients, the risk of ventricular tachyarrhythmias remains higher in ICMP patients in comparison with NICMP patients. Renal function is improved in the NICMP group after the treatment. Long-term mortality is similar over a one-year follow-up.


2005 ◽  
Vol 28 (10) ◽  
pp. 1145-1145 ◽  
Author(s):  
SANJIV M. NARAYAN ◽  
JOSEPH M. SMITH ◽  
MICHAEL E. CAIN

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Mustafa Husaini ◽  
Yitschak Biton ◽  
Scott McNitt ◽  
Wojciech Zareba ◽  
Arthur J Moss ◽  
...  

Background: The Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) showed that patients with ischemic cardiomyopathy (ICM) had similar reductions in clinical events with implanted CRT-D vs. ICD-only when compared to patients with non-ischemic cardiomyopathy (NICM). Frequency of revascularizations may serve as a surrogate for severity of coronary artery disease in patients with ICM and severely reduced left ventricular ejection fraction. However, it is unknown whether the number of revascularizations plays a role in clinical outcomes in ICM patients implanted with CRT-D vs. ICD-only. Methods: Using a multivariable analysis of MADIT-CRT data, we evaluated the effect of CRT-D vs. ICD-only on combined heart failure (HF) or death and combined ventricular tachycardia (VT), ventricular fibrillation (VF) or death in ICM patients by the number of pre-enrollment revascularizations (1 or ≥ 2 revascularizations) compared to those with no need for revascularization. Follow-up over a median period of 5.6 years for HF/death and 4.0 years for VT/VF/death was assessed among 1374 ICM patients with a Left Bundle Branch Block (LBBB). Results: There was a significant and similar risk reduction with CRT-D vs. ICD-only in HF/death in all three sub-groups: ICM with no need for revascularization (HR 0.45 [0.26-0.80]; p < 0.006), ICM with one revascularization (HR 0.46 [0.31-0.69]; p <0.001), and ICM with 2 or more revascularization (HR 0.50 [0.30-0.84]; p = 0.008). However, significant risk reduction of VT/VF/death with CRT-D vs. ICD-only was only observed in patients with no need for revascularization (HR 0.52 [0.30-0.89]; p = 0.017), less so in those with ICM with one revascularization (HR 0.72 [0.49-1.06]; p = 0.10), and no reduction was seen in those with ICM with 2 or more revascularization (HR 0.94 [0.54-1.62]; p = 0.81). Conclusions: In ischemic cardiomyopathy patients, CRT-D vs. ICD-only is associated with a significant risk reduction in heart failure events or death irrespective of the frequency of pre-enrollment revascularization procedures; however, the benefit of CRT-D vs. ICD-only to reduce ventricular tachyarrhythmias is attenuated with the increasing number of revascularization procedures.


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