Keisuke Kida

Reversible ventricular dysfunction takotsubo cardiomyopathy

Recently, many cardiologists have recognized the existence of a rapidly reversible form of heart failure of unknown origin characterized by a takotsubo‐shaped, dyskinetic left ventricle on left ventriculography.

The exercise training effects of skeletal muscle strength and muscle volume to improve functional capacity in patients with myocardial infarction

BACKGROUND No previous studies have fully investigated the exercise training effect on the skeletal muscle strength and volume to improve the exercise capacity in patients with myocardial infarction (MI). The present study was performed based on a hypothesis that the relationship between exercise capacity, skeletal muscle strength and volume might be changed by the amount of skeletal muscle volume in MI patients up to 3 months after the onset. METHODS Seventy patients with MI underwent symptom-limited cardiopulmonary exercise testing using a treadmill. The lower limb muscle volume (MV) was evaluated according to electrical impedance analysis and the maximal knee extension strength (Peak torque: PT) was measured by a Biodex. All patients participated in 12-week exercise training program. The subjects were divided into 2 groups on the basis of MV: Group H, MV>==22 kg; Group L, MV<22 kg. Delta values were calculated as follows: the value at 3 months minus the value at 1 month. RESULTS A positive and significant correlation was observed between the delta PT and delta peak VO(2) (r=0.50, p<0.005) only in the L group. No significant correlation was observed between the delta peak VO(2) and the delta lower limb MV or between the delta lower limb MV and the delta PT in the 2 groups. CONCLUSIONS Cardiac rehabilitation program combined with resistance and aerobic training improved exercise capacity and increased not the skeletal muscle volume but the skeletal muscle strength in patients with MI in their recovery phase. It was presumed that the improvement of exercise capacity was determined by the skeletal muscle strength not by the muscle volume especially in MI patients with low muscle volume.

The relation between Geriatric Nutritional Risk Index and muscle mass, muscle strength, and exercise capacity in chronic heart failure patients.

a Graduate School of Health Sciences, Kobe University, Kobe, Japan b Department of Rehabilitation Medicine, St. Marianna University School of Medicine Hospital, Kawasaki, Japan c Department of Physical Therapy, Tokushima Bunri University, Tokushima, Japan d Faculty of Sport Sciences, Waseda University, Tokorozawa, Japan e Division of Cardiology, St. Marianna University Toyoko Hospital, Kawasaki, Japan f Department of Cardiology, St. Marianna University Yokohama City Seibu Hospital, Yokohama, Japan g Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC, USA h Department of Orthopedic Surgery, St. Marianna University School of Medicine, Kawasaki, Japan i Division of Cardiology, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan

Simple exercise echocardiography using a Master's two-step test for early detection of pulmonary arterial hypertension

BACKGROUND Early detection of pulmonary arterial hypertension (PAH) is indispensable, although, echocardiography at rest alone does not provide sufficient evidence for it. Here, this study aimed to investigate the usefulness of simple exercise echocardiography using a Masters two-step test for detecting early PAH. METHODS This study included 52 connective tissue disease patients who had mild symptoms in World Health Organization functional classification 2, suspected as having early PAH, and underwent exercise echocardiography and right heart catheterization. Echocardiography was performed before and after the Masters two-step exercise test; the study patients were classified into the non-PAH (mean pulmonary arterial pressure <25 mmHg, n=37) or PAH (mean pulmonary arterial pressure ≥25 mmHg, n=15) groups. RESULTS Rest systolic pulmonary artery pressure estimated using echocardiography did not significantly differ between the two groups; however, a significant difference in post-exercise systolic pulmonary artery pressure was found (non-PAH, 58.8±10.8 mmHg; PAH, 80.2±14.3 mmHg, p<0.0001). The multiple logistic regression analysis indicated post-exercise systolic pulmonary artery pressure as an independent predictor of PAH (p=0.013). The area under the curve by post-exercise systolic pulmonary artery pressure was 0.91 for PAH. Post-exercise systolic pulmonary artery pressure ≥69.6 mmHg predicted PAH with the sensitivity of 93% and the specificity of 90%. CONCLUSIONS Simple exercise echocardiography using the Masters two-step test could detect PAH in mildly symptomatic connective tissue disease patients. The usefulness of this method should be verified for the early detection of PAH.

Relationship between sleep apnea syndrome and sleep blood pressure in patients without hypertension.

BACKGROUND AND PURPOSE Ambulatory blood pressure monitoring (ABPM) provides an accurate assessment of blood pressure (BP) and shows non-dipper BP pattern in many sleep apnea syndrome (SAS) patients with hypertension (HTN); however, little information is available on the relationship between the severity of SAS and circadian BP changes in SAS patients without HTN. This study investigated whether SAS patients without HTN would have different BP courses in the severity of SAS. METHODS AND SUBJECTS Seventy-four consecutive outpatients without HTN [systolic BP (BPs) at clinic <140mmHg and/or diastolic BP (BPd) at clinic <90mmHg], who received no antihypertensives, underwent overnight polysomnography (PSG) and ABPM. The apnea-hypopnea index (AHI) was calculated from the PSG results; patients were stratified into the following 4 groups based on their AHI: non-SAS, mild-, moderate-, or severe-SAS. RESULTS The diurnal BPs and BPd showed no differences in the severity of SAS; however, the sleep BPs, lowest BPs, and pre-awake BPs were significantly higher in the severe-SAS group than the non-SAS group (p=0.02, p=0.04, and p=0.006, respectively). The sleep BPd and pre-awake BPd were significantly higher in the severe-SAS than the non-SAS (p=0.01 and p=0.0003, respectively) and mild-SAS (p=0.01 and p=0.008, respectively) groups. CONCLUSIONS The results of this study suggested that SAS affected nocturnal BP elevation even in SAS patients without HTN. The diurnal BP showed no difference in the severity of SAS; however, the severe-SAS group revealed significant nocturnal BP elevation.

Peak time of acute coronary syndrome in patients with sleep disordered breathing.

BACKGROUND Recently, sleep disordered breathing (SDB) has gained attention in the field of cardiology. Until now, no study describing the relationship between acute coronary syndrome (ACS) and SDB has been carried out in Japan. METHODS Among ACS patients admitted to our hospital, 44 patients (mean age 60.6+/-13.5 years) who received a portable polysomnography to measure apnea hypopnea index (AHI) were selected for this study. The circadian pattern of ACS onset was studied in 6-h intervals. In addition, all subjects were divided into three groups according to AHI severity (AHI < 5, 5 < or = AHI < 15, and 15 < or = AHI). Then, a comparative study between peak time of ACS and AHI severity was conducted for each group. RESULTS In the AHI < 5 group, 66.0% patients suffered from ACS between 12:00 h and 18:00 h and 17.0% between 18:00 h and 24:00 h, and a total of 83.0% patients had ACS between 12:00 h and 24:00 h. In the 5 < or = AHI < 15 group, 49.9% patients had ACS between 24:00 h and 06:00 h, 16.7% patients between 06:00 h and 12:00 h. 12:00-18:00 h and 18:00-24:00 h showed no significant difference. All 22 patients in the 15 < or = AHI group suffered from ACS between 24:00 h and 12:00 h. CONCLUSION The results of this study suggest a possible relationship between SDB and the onset of ACS between midnight to morning.

Association between heart rate at rest and myocardial perfusion in patients with acute myocardial infarction undergoing cardiac rehabilitation – a pilot study

Introduction This study was conducted to determine if there was a link among heart rate at rest (rHR), muscle volume changes, and single photon emission computed tomography (SPECT) parameters after 6-month cardiac rehabilitation in patients with acute myocardial infarction (AMI). Material and methods Twenty-nine consecutive AMI patients (mean age: 63.0 ±9.1 years) who received appropriate percutaneous coronary intervention on admission were enrolled. 99mTc-Sestamibi myocardial SPECT images were obtained at the early (30 min) and delayed (4 h) phases after tracer injection at 2 weeks (0M) and 6 months (6M) after the onset of AMI. Within a few days of SPECT, all patients underwent cardiopulmonary exercise test for evaluation of cardiac rehabilitation effects. Before the initiation of exercise test, leg muscle volume was measured. All patients were stratified into the ≥ 70 beats per minute (bpm) (n = 15) or < 70 bpm (n = 14) group based on rHR at 6M. Results There were no significant differences in the recanalization time, peak cardiac enzyme, or initial left ventricular ejection fraction between the two groups. After the 6-month training, the muscle volume changes in the lower limbs (< 70 bpm, 0.23 ±0.22; ≥ 70 bpm, –0.07 ±0.26, p < 0.05) were significantly greater in the < 70 bpm group than the ≥ 70 bpm group. The decreased rate of rHR had a significant correlation with the improved global severity (r = 0.62, p = 0.001) and extent (r = 0.48, p = 0.017) of left ventricle evaluated by 99mTc-Sestamibi myocardial SPECT delayed phase. Conclusions The result of this preliminary study demonstrated that improved myocardial perfusion was closely related to decreased rHR after cardiac rehabilitation.

Influence of exercise-induced pulmonary hypertension on exercise capacity in asymptomatic degenerative mitral regurgitation.

BACKGROUND Exercise capacity is helpful in the management of patients with mitral regurgitation (MR). However, the determinants of exercise capacity reduction in MR have remained unclear. This study was designed to objectively assess exercise capacity, identify the echocardiographic predictors of exercise capacity, and investigate its impact on development of symptoms in asymptomatic degenerative MR. METHODS A total of 49 consecutive asymptomatic patients (age, 58.9±13.1 years; 82% males) with at least moderate degenerative MR (effective regurgitant orifice area=0.40±0.14cm(2); regurgitant volume=60.9±19.6mL) underwent the symptom-limited cardiopulmonary exercise testing for assessing exercise capacity (peak oxygen uptake, peak V˙O2; the minute ventilation/carbon dioxide production, V˙E/V˙CO2 slope). All patients also underwent exercise stress echocardiography for detecting exercise-induced pulmonary hypertension (EIPH) defined by systolic pulmonary arterial pressure (SPAP) ≥60mmHg. RESULTS The mean peak V˙O2 was 22.6±5.1mL/kg/min (86.7±14.1% of age, gender-predicted); peak V˙O2 widely varied (48-121% of predicted), and was markedly reduced (<80.4% of predicted) in 24% of the study patients. The patients with EIPH had lower 2-year symptom-free survival than those without EIPH (p=0.003). The multivariable analysis demonstrated that EIPH was an independent echocardiographic determinant of peak V˙O2 (p=0.001) and V˙E/V˙CO2 slope (p=0.021). Furthermore, the area under curve of age- and gender-adjusted exercise SPAP was 0.88 (95% confidence interval: 0.78-0.97) for reduced exercise capacity. CONCLUSIONS In asymptomatic moderate to severe degenerative MR, EIPH was independently associated with exercise capacity and predicted the occurrence of symptoms. Exercise stress echocardiography is an important tool in managing patients with asymptomatic degenerative MR.

Influence of Pulmonary Vascular Reserve on Exercise‐Induced Pulmonary Hypertension in Patients with Systemic Sclerosis

Exercise‐induced pulmonary hypertension (PH) is considered as an early preclinical functional phase of resting PH in systemic sclerosis (SSc). In this study, we investigated the prevalence of exercise‐induced PH in patients with SSc and evaluated the influence of pulmonary vascular reserve on exercise‐induced PH.

Assessment of Transthyretin Combined With Mini Nutritional Assessment on Admission Provides Useful Prognostic Information in Patients With Acute Decompensated Heart Failure

Decreased Transthyretin (TTR) can be observed in heart failure patients with malnutrition evaluated by the Mini Nutritional Assessment (MNA). This study investigated whether a combination of different nutritional assessment methods would be useful for assessing prognosis in patients with acute decompensated heart failure (ADHF).This prospective study included 52 patients with ADHF (mean age, 71.1 ± 14.7 years; men 55.8%) who were admitted to our hospital between June 2012 and August 2013. On admission, nutritional status was evaluated according to levels of TTR and the MNA. Of 52 patients, 28 (53.8%) had TTR < 15 mg/dL, 39 (75.0%) had malnutrition or were at risk of malnutrition (MNA score ≤ 23.5), and 21 (40.4%) were categorized into group L (MNA score ≤ 23.5 and TTR < 15 mg/dL). Readmission due to worsening heart failure occurred in 12 patients (23.1%), and there were 4 (7.7%) allcause deaths. The 1-year event-free survival rates in group L and the remaining patients (group O) were 27.7% and 85.6%, respectively (P = 0.001). Using Cox multivariate analysis, group L also had a poorer prognosis (hazard ratio 4.35, 95% confidence interval 1.26-17.74, P = 0.020).MNA revealed that 75% of patients with ADHF had malnutrition or were at risk of malnutrition. The combination of low MNA and low TTR on admission can predict the prognosis of patients with ADHF.