Efficacy and safety of exercise rehabilitation in patients with hypertrophic cardiomyopathy.

BACKGROUND: While physical rehabilitation has been shown to be beneficial and safe for patients suffering from heart failure, data on rehabilitation for hypertrophic cardiomyopathy (HCM) patients are limited. METHODS: Forty-five HCM patients participated in an exercise rehabilitation program. Exercise capacity was measured in metabolic equivalent of task (METs) units and functional status was defined according to the New York Heart Association (NYHA). Self-reported measurements addressed the quality of life and daily life function. RESULTS: Of the 45 participants, 32 completed at least 3 months of rehabilitation and had data from two sequential exercise tests. A significant increase in exercise capacity (from mean 5.3 to 6.7 METs, p=0.01), was achieved at higher peak heart rates. Eighteen patients (56%) who showed improvement in exercise capacity did not differ in their NYHA class, clinical, electrocardiographic, or echo-Doppler parameters compared to those who did not improve. The benefit from training was associated with a lower exercise capacity at baseline and was most pronounced in those capable of less than 6.8 METs (p=0.008). No significant arrhythmias or adverse events were recorded in HCM patients during participation. In ∼40% of participants, training improved the subjective perception of functional capacity and quality of life; only 4 patients (9%) discontinued their participation due to discomfort during or following training. The improvement in exercise capacity was comparable between HCM and a reference group of dilated cardiomyopathy patients. CONCLUSIONS: Exercise rehabilitation appears to be applicable and safe in HCM. It mainly benefits patients suffering from significant functional limitation. Larger prospective studies are needed to validate these findings and better characterize patients expected to benefit from these programs.

Catecholamine response to exercise in patients with non-obstructive hypertrophic cardiomyopathy.

KEY POINTS: Intense physical activity, a potent stimulus for sympathetic nervous system activation, is thought to increase the risk of malignant ventricular arrhythmias among patients with hypertrophic cardiomyopathy (HCM). As a result, the majority of patients with HCM deliberately reduce their habitual physical activity after diagnosis and this lifestyle change puts them at risk for sequelae of a sedentary lifestyle: weight gain, hypertension, hyperlipidaemia, insulin resistance, coronary artery disease, and increased morbidity and mortality. We show that plasma catecholamine levels remain stably low at exercise intensities below the ventilatory threshold, a parameter that can be defined during cardiopulmonary exercise testing, but rise rapidly at higher intensities of exercise. These findings suggest that cardiopulmonary exercise testing may be a useful tool to provide an individualized moderate-intensity exercise prescription for patients with HCM. ABSTRACT: Intense physical activity, a potent stimulus for sympathetic nervous system activation, is thought to increase the risk of malignant ventricular arrhythmias among patients with hypertrophic cardiomyopathy (HCM). However, the impact of exercise intensity on plasma catecholamine levels among HCM patients has not been rigorously defined. We conducted a prospective observational case-control study of men with non-obstructive HCM and age-matched controls. Laboratory-based cardiopulmonary exercise testing coupled with serial phlebotomy was used to define the relationship between exercise intensity and plasma catecholamine levels. Compared to controls (C, n = 5), HCM participants (H, n = 9) demonstrated higher left ventricular mass index (115 ± 20 vs. 90 ± 16 g/m2 , P = 0.03) and maximal left ventricular wall thickness (16 ± 1 vs. 8 ± 1 mm, P < 0.001) but similar body mass index, resting heart rate, peak oxygen consumption (H = 40 ± 13 vs. C = 42 ± 7 ml/kg/min, P = 0.81) and heart rate at the ventilatory threshold (H = 78 ± 6 vs. C = 78 ± 4% peak heart rate, P = 0.92). During incremental effort exercise in both groups, concentrations of adrenaline and noradrenaline were unchanged through low- and moderate-exercise intensity until reaching a catecholamine threshold (H = 82 ± 4 vs. C = 85 ± 3% peak heart rate, P = 0.86) after which levels of both molecules rose rapidly. In patients with mild non-obstructive HCM, plasma catecholamine levels remain stably low at exercise intensities below the ventilatory threshold but rise rapidly at higher intensities of exercise. Routine cardiopulmonary exercise testing may be a useful tool to provide an individualized moderate-intensity exercise prescription for patients with HCM.

A Control Theory-Based Pilot Intervention toIncrease Physical Activity in Patients WithHypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HC) is the most common genetic heart disease. Consensus guidelines recommend restriction from competitive and/or high-intensity physical activities; however, sufficient light-moderate intensity physical activity remains important for health and wellbeing. This study aimed to evaluate the effectiveness and appeal of a control theory-based intervention to increase physical activity levels in individuals with HC. A pre to post trial of HC participants (n = 25) recruited from May 2016 to April 2017 from a specialized, multidisciplinary clinic was conducted. A 12-week intervention based on principles of control theory was developed. The primary outcome measures were self-reported leisure and transport-related physical activity. The mean age of participants was 42 ± 13years and the majority were men (n = 15, 60%). Although both the primary (self-report) and secondary (objective) outcome measures of physical activity increased, such as leisure-time physical activity: 98 ± 132 minutes per week to 151 ± 218 minutes per week, these were not statistically significant. Secondary outcome measures improved, including physical health-related quality of life (HR-QoL; 43 ± 6 to 50 ± 8, p = 0.004), self-efficacy (14 ± 3 to 16 ± 4, p <0.001), and the number of barriers identified (4 ± 3 to 3 ± 2 barriers, p = 0.02). This simple, easy-to-administer intervention to promote physical activity in HC improved willingness to undertake physical activity, increased self-efficacy, and improved physical quality of life. This may help patients overcome perceived barriers and a lack of confidence regarding physical activity, with the ultimate goal to improve overall health outcomes in HC patients.

Effect of Moderate-Intensity Exercise Training on Peak Oxygen Consumption in Patients With Hypertrophic Cardiomyopathy: A Randomized Clinical Trial.

Importance: Formulating exercise recommendations for patients with hypertrophic cardiomyopathy is challenging because of concern about triggering ventricular arrhythmias and because a clinical benefit has not been previously established in this population. Objective: To determine whether moderate-intensity exercise training improves exercise capacity in adults with hypertrophic cardiomyopathy. Design, Setting, and Participants: A randomized clinical trial involving 136 patients with hypertrophic cardiomyopathy was conducted between April 2010 and October 2015 at 2 academic medical centers in the United States (University of Michigan Health System and Stanford University Medical Center). Date of last follow-up was November 2016. Interventions: Participants were randomly assigned to 16 weeks of moderate-intensity exercise training (n = 67) or usual activity (n = 69). Main Outcomes and Measures: The primary outcome measure was change in peak oxygen consumption from baseline to 16 weeks. Results: Among the 136 randomized participants (mean age, 50.4 [SD, 13.3] years; 42% women), 113 (83%) completed the study. At 16 weeks, the change in mean peak oxygen consumption was +1.35 (95% CI, 0.50 to 2.21) mL/kg/min among participants in the exercise training group and +0.08 (95% CI, -0.62 to 0.79) mL/kg/min among participants in the usual-activity group (between-group difference, 1.27 [95% CI, 0.17 to 2.37]; P = .02). There were no occurrences of sustained ventricular arrhythmia, sudden cardiac arrest, appropriate defibrillator shock, or death in either group. Conclusions and Relevance: In this preliminary study involving patients with hypertrophic cardiomyopathy, moderate-intensity exercise compared with usual activity resulted in a statistically significant but small increase in exercise capacity at 16 weeks. Further research is needed to understand the clinical importance of this finding in patients with hypertrophic cardiomyopathy, as well as the long-term safety of exercise at moderate and higher levels of intensity. Trial Registration: clinicaltrials.gov Identifier: NCT01127061.

Blood pressure dynamics during exercise rehabilitation in heart failure patients.

Background Patients suffering from heart failure (HF) may demonstrate an abnormal blood pressure response to exercise (ABPRE), which may revert to a normal one following medical treatment. It is assumed that this change correlates positively with prognosis and functional aspects. The aim of this study was to characterize patients with ABPRE and assess ABPRE normalization and the correlation with clinical and functional outcomes. Methods In the study, 651 patients with HF who underwent cardiac rehabilitation (CR) were examined. Patients who presented an ABPRE during stress testing were identified and divided into those who corrected their initial ABPRE following CR and those who did not. Results Pre-rehabilitation ABPRE was present in 27% of patients, 68% of whom normalized their ABPRE following CR. Two parameters were independently predictive of failure to normalize the blood pressure response: female gender (odds ratio (OR) 3.5; 95% confidence interval (CI) 1.4-9.0) and decreased systolic function (OR 3.2; 95% CI 1.0-9.4). Patients with hypertrophic cardiomyopathy demonstrated higher rates of ABPRE normalization than patients with other causes of HF (93% vs. 62%, respectively, P = 0.03). The research population exhibited an average improvement in exercise capacity (4.7 to 6.4 metabolic equivalents (METS), P < .001), ejection fraction (35.4% to 37.7%, P < .001) and percentage of patients with New York Heart Association (NYHA) class 3-4 (50% to 43.4%, P = .123). The group who normalized their ABPRE exhibited greater improvement. Conclusions Amongst a population of patients suffering from HF, an ABPRE was normalized following CR in two thirds of patients. Female gender and a reduced systolic function independently predicted the failure to correct the ABPRE, while patients with hypertrophic cardiomyopathy demonstrated exceptionally high rates of normalization.

Efficacy of exercise training in symptomatic patients with hypertrophic cardiomyopathy: results of a structured exercise training program in a cardiac rehabilitation center.

BACKGROUND: Recent data suggest that exercise training (ET) confers significant symptomatic and functional improvements in patients with diastolic dysfunction, and thus may be beneficial in patients with hypertrophic cardiomyopathy (HCM). However, there are no data regarding the safety or efficacy of ET in HCM patients. DESIGN: A prospective non-randomized intervention design was used. METHODS: We enrolled 20 patients with symptomatic HCM, significantly limited in everyday activity, into a supervised cardiac rehabilitation exercise program. RESULTS: Patients were 62 ± 13 years old, in New York Heart Association (NYHA) functional class II (35%) or III (65%), had a mean interventricular septum dimension of 17 ± 5 mm and left ventricular ejection fraction (LVEF) of 53 ± 15%. Left ventricular outflow gradient was present at rest in nine patients (mean 51 ± 24 mm Hg) and six patients had an implantable defibrillator. Exercise prescription was based on heart rate reserve (HRR) determined from a symptom-limited graded exercise stress test. Exercise intensity was gradually increased from 50% to 85% of the HRR over the training period. Patients completed an average of 41 ± 8 hours of aerobic ET. No adverse events or sustained ventricular arrhythmias occurred during the training program. Functional capacity, assessed by a graded exercise test, improved from 4.7 ± 2.2 to 7.2 ± 2.8 metabolic equivalents (METs) (p = 0.01). NYHA functional class improved from baseline by ≥ 1 grade in 10 patients (50%) and none experiencing deterioration during follow-up. CONCLUSIONS: The present study suggests that patients with HCM who remain symptomatic despite medical therapy may achieve considerable functional improvement through a supervised ET program.

Perceptions of activity and vocational status in women with cardiac illness.

The purpose of this descriptive study was to determine the perceptions of activity and vocational status in women with cardiac illness. A convenience sample of 20 women with the diagnosis of coronary heart disease or hypertrophic cardiomyopathy participated. Subjects underwent an audiotaped interview, using a semistructured interview guide, which was then transcribed into the Ethnograph software program (Qualis Research Associates, Salt Lake City, UT). Transcripts were analyzed for common themes via content analysis. There were four themes identified for activity: variable activity patterns, fatigue, guilt, and depression. There were four themes identified for vocational status: desire to work, social aspects of work, unpaid work, and struggle to maintain the status quo. In conclusion, the themes of fatigue, guilt over unmet activity expectations, and the common occurrence of unpaid work validated prior research findings. The themes of variable patterns of activity management, feelings of depression about lowered activity levels, the desire to return to a prior vocation, the importance of the social nature of work, and the struggle to balance both home and work roles were new findings.

O tratamento da miocardiopatia hipertrófica por meio de um marcapasso DDD capaz de registrar o eletrograma intramiocárdico / The intracardiac electrogram in a patient with hypertrophic obstructive cardiomyopathy treated with DDD pacing

Paciente do sexo feminino de 48 anos, portadora de miocardiopatia hipertrófica obstrutiva refratária ao tratamento clínico, implantou um marcapasso DDD com capacidade de registrar o eletrograma intramiocárdico por telemetria, sob a forma da resposta ventricular evocada (VER). O gradiente sistólico máximo na via de saída do ventrículo esquerdo (GSVSVE) obtido por ecocardiograma bidimensional com Doppler foi reduzido pela estimulaçäo DDD com intervalo atrioventricular curto (50ms) de um valor controle de 121mmHg para 100mmHg. Um valor inferior foi encontrado nas programaçöes mensais subsequentes, acompanhado de modificaçöes na VER. Nestas avaliaçöes, intervalos atrioventriculares progressivamente reduzidos (150, 100 e 50ms) determinaram variaçöes agudas no GSVSVE também associadas com alteraçöes no traçado da VER, tais como reduçäo na amplitude do sinal no tempo de 150ms. Fica aberta perspectiva de um estudo para correlacionar o eletrograma intracardíaco com o GSVSVE e o intervalo AV, buscando-se um ajuste automático do marcapasso para manter a menor obstruçäo intraventricular na miocardiopatia hipertrófica obstrutiva.

[Results of long-term verapamil treatment of patients with hypertrophic cardiomyopathy]. / Wyniki przewleklego leczenia verapamilem u chorych z kardiomiopatia przerostowa.

In 50 patients with different forms of hypertrophic cardiomyopathy the effect of many months (mean 23.3 +/- 15.7) therapy with verapamil was estimated. Interventricular septum thickness, isovolumetric relaxation period (IRP), "a" wave amplitude were evaluated as well as changes of parameters indirectly testifying to intraventricular obstruction such as: abnormal systolic anterior mitral leaflet motion (SAM) and midsystolic aortic valve closure (AVC). Pre- and post therapy physical efficacy was estimated basing on effort duration. Results were compared with those observed in a group of 20 patients with hypertrophic cardiomyopathy not treated with calcium channel antagonists. Verapamil therapy resulted in inhibition of a disease progression and in diminution of interventricular septum thickness respectively in 74% and 48% of patients. Differences are significant in comparison with a control group. Characteristics of diastole was improved almost in a half of verapamil patients. In the majority of cases, active diastolic period improvement was referred to patients with nonobstructive cardiomyopathy forms and corresponded with their physical fitness improvement. Verapamil resulted in diminution or regression of SAM and AVC in patients with obstructive forms and most likely caused physical efficacy improvement in some of them. The study also confirmed that the group of patients with hypertrophic cardiomyopathy is not homogenous one with regard to morphology of hypertrophy, hemodynamics, disease progression and response to therapy. Observed differences do not always depend on a cardiomyopathy form which suggests that the applied nowadays classification is not sufficient.

Exercise performance after septal myotomy and myectomy in patients with obstructive hypertrophic cardiomyopathy.

The effect of left ventriculomyotomy and myectomy on exercise capacity and cardiac function in patients with obstructive hypertrophic cardiomyopathy has not previously been determined. In this study, 29 patients were evaluated during graded treadmill exercise before and after operation. Postoperatively, 27 of 29 patients reported symptomatic improvement and had greatly reduced left ventricular outflow gradient. Twenty-five of 28 patients (89 percent) attained higher exercise levels after operation, and this was accompanied by an increase in total body oxygen consumption from 16 to 21 ml/min per kg (P less than 0.005). A significant increase in cardiac index during maximal exercise also accompanied this improved exercise performance (5.0 to 5.7 liters/min per m2, P less than 0.05). The increase in maximal cardiac index was associated with greater desaturation of mixed venous blood (34 to 24 percent, P less than 0.02) in patients with preoperative angina. At a given level of mixed venous oxygen saturation (30 percent), overall mean cardiac index was higher postoperatively (4.6 to 5.2 liters/min per m2, P less than 0.05). These results suggest that, although several mechanisms probably contribute to symptomatic improvement after myotomy and myectomy, enhanced cardiac performance plays an important role in the majority of patients.