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Biomedical subjects

N Doba

Publications and source records attributed to N Doba.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Cardiac rehabilitation in acute coronary syndrome].

Recently, there have been a great advancement in diagnosis and treatment of ACS, and therefore the modality of cardiac rehabilitation has also been greatly changed. In the era of primary intervention, the hospital stay after ACS has been grossly shortened even within several days. Since morphologies and functions of the diseased coronary arteries and the left ventricle are already correctly and precisely assessed before reaching CCU, the initiation and subsequent progression of cardiac rehabilitation can be performed with great ease. On the contrary to these benefits, however, the time for patients education after ACS is greatly limited. Lifestyle modifications that are thought to be well established key elements in modern preventative cardiology has to be accomplished after discharge from the hospital. These new trends in cardiac rehabilitation must be more efficacious than previous painstaking inhospital rehabilitation procedures and can be accepted widely as economically feasible and safe treatment modalities after ACS.

Acute Disease↗
PubMed1997

The relationship of hyperinsulinemic state to left ventricular hypertrophy, microalbuminuria, and physical fitness in borderline and mild hypertension.

The relationship of the hyperinsulinemic state to left ventricular hypertrophy, left ventricular geometric patterns, microalbuminuria, and physical fitness were studied in 52 middle-aged unmedicated men with borderline and mild hypertension. Left ventricular mass index and relative wall thickness were assessed by echocardiography. Physical fitness was determined by symptom-limited maximal treadmill stress testings. The urinary concentration of microalbumin and C-peptide was measured in 24-h urine samples by radioimmunoassey. The 24-h urinary C-peptide excretion rate was correlated with left ventricular mass index (r = 0.46), relative wall thickness (r = 0.41), treadmill time (r = -0.35), normalized treadmill time (r = -0.52), systolic blood pressure at peak exercise (r = 0.29), and 24-h urinary microalbumin excretion (r = 0.48). Stepwise multiple regression analysis identified the left ventricular mass index, the 24-h urinary albumin excretion, and the normalized treadmill time as variables in the equation for the 24-h urinary C-peptide excretion. Thus, the hyperinsulinemic state is related to left ventricular hypertrophy, microalbuminuria, and impaired physical fitness in patients with borderline and mild hypertension.

Adult↗
PubMed1997

Effects of long-term antihypertensive therapy on physical fitness of men with mild hypertension.

This study was conducted to investigate the effects of long-term administration of a calcium-channel antagonist (nifedipine) and a beta-blocker (acebutolol) on physical fitness in men with mild hypertension. All subjects underwent symptom-limited treadmill stress testing and routine echocardiographic studies. Twenty-two subjects who had either a causal diastolic blood pressure of more than 105 mmHg or a left ventricular mass index (LVMI) of 125 g/m2 or more during follow-up were assigned to receive medical therapy. The other 31 men who did not meet either criterion were continuously followed-up without medication. Among the 22 treated men, the age-adjusted treadmill time (normalized treadmill time, TMTn) significantly decreased before the initiation of medication, while 31 untreated men showed no change in TMTn throughout the study. The 22 treated subjects were subsequently divided into two groups; 13 were given nifedipine and 9 were given acebutolol. All treated subjects were followed-up for more than 3 years. After treatment, the two groups showed similar reductions in blood pressure and LVMI, but a different outcome for TMTn: TMTn increased from 104 +/- 8% to 115 +/- 16% in subjects given nifedipine (p < 0.05) and decreased from 106 +/- 12% to 99 +/- 10% (p < 0.01) in those given acebutolol. Thus, the physical fitness of subjects who required medication significantly deteriorated without medication; their physical fitness improved after treatment with a calcium-channel antagonist and deteriorated after treatment with a beta-blocker.

Acebutolol↗
PubMed1997

[Clinical significance of valvular regurgitation during long-term antihypertensive therapy in patients with mild to moderate essential hypertension].

Changes in valvular function and blood pressure level during long-term pharmacological anti-hypertensive therapy were investigated in patients with mild to moderate essential hypertension. Sixty-seven patients with hypertension (mean [+/-SD] 60 +/- 10 years) were followed up for 5.4 +/- 1.6 years with antihypertensive medication. During the follow-up period, valvular dysfunction was assessed by color Doppler echocardiography. Increased mitral valve regurgitation > or = grade II and/or aortic valve regurgitation > or = grade II were aggravated in 17 patients, whereas the other 50 patients did not reveal any significant changes in valvular functions. Systolic blood pressure and end-systolic wall stress at the end of the follow-up period were higher in the aggravated group (156 +/- 30 mmHg and 79 +/- 23 dyne/cm2) than in the unchanged group (143 +/- 17 mmHg and 63 +/- 18 dyne/cm2). Dimensions of the left atrium and left ventricle at both systole and diastole were enlarged in the aggravated group (37 +/- 4 to 40 +/- 4, 31 +/- 4 to 33 +/- 4 and 48 +/- 3 to 51 +/- 3 mm, respectively), but not in the unchanged group. Nine patients in the aggravated group received additional treatment with imidapril hydrochloride over 6 months in an attempt to further reduce blood pressure levels, resulting in significant improvements in systolic blood pressure (151 +/- 12 to 129 +/- 7 mmHg), diastolic blood pressure (91 +/- 4 to 79 +/- 8 mmHg), left atrial dimension (41 +/- 3 to 39 +/- 3 mm) and left ventricular end-diastolic dimension (49 +/- 4 to 48 +/- 3 mm). Adequate pharmacological intervention can ameliorate valvular dysfunction, left ventricular enlargement and increased ventricular wall stress.

Adult↗
PubMed1997

[Ultrasound examination for hypertension].

The echocardiographic determination of left ventricular mass is useful to evaluate the severity and the prognosis of hypertension. In addition to this determination, the echocardiographic assessment of left ventricular morphology is also proposed as one of important parameters to implicate the prognosis. Recently, the clinical significance of intimal-media thickness, plaque, and diameter of carotid artery obtained by an ultrasound examination for hypertension has been discussed. While these parameters correlate well with blood pressure level and left ventricular mass, further studies are needed to establish the usefulness of the ultrasound examination of carotid artery. As a tool for research purposes, ultrasound examination is also applicable to examine organ blood flow, arterial distensibility, and arterial endothelial function. Thus, ultrasound examination for hypertension is promising either in clinical practices and research purposes.

Blood Flow Velocity↗
PubMed1997

[Studies on residual cardiovascular dysfunction in patients receiving long-term antihypertensive treatment of calcium channel blockers: with special reference to left ventricular hypertrophy, and impairments of left ventricular diastolic function and carotid arterial distensibility].

Residual cardiovascular dysfunctions including left ventricular hypertrophy, and impairment of left ventricular diastolic function and carotid arterial distensibility were investigated in hypertensive patients treated with calcium channel blockers for more than 1 year. Ultrasonographic examinations of the heart and carotid artery were performed in patients treated with calcium channel blocker alone for more than 1 year (n = 45) and in age-, sex- and weight-matched control subjects (n = 29). The following parameters were obtained: left ventricular mass index, cardiac diastolic function (A/E ratio) and carotid arterial distensibility (Distens). Hypertensive subjects were re-examined under the same conditions with the same parameters after 10 +/- 5 months. Patients with hypertension revealed no significant changes in these three parameters after 10 +/- 5 months Patients with left ventricular hypertrophy (n = 20) revealed significant impairments in diastolic function and carotid arterial distensibility (A/E = 1.42 +/- 0.25, Distens = 2.4 +/- 1.3% kPa) compared to those without left ventricular hypertrophy (n = 25) (A/E = 1.18 +/- 0.29, Distens = 3.8 +/- 1.7% kPa, p < 0.05). Patients without left ventricular hypertrophy had significantly impaired cardiovascular functions compared to the normal control group (A/E = 1.03 +/- 0.27, Distens = 6.3 +/- 2.2% kPa, p < 0.05, p < 0.01 respectively). Therefore, only reduction of blood pressure with calcium channel blocker may not be enough to improve cardiovascular organ damage, especially in patients with residual left ventricular hypertrophy, and such residual functional deteriorations must be corrected probably with another pharmaceutical modality.

Aged↗
PubMed1996

An impaired carotid sinus distensibility and baroreceptor sensitivity alter autonomic activity in patients with effort angina associated with significant coronary artery disease.

Baroreceptor sensitivity and carotid sinus distensibility were lower in patients with angina associated with significant coronary artery disease than in patients with vasospastic angina. Baroreceptor sensitivity was significantly correlated with carotid sinus distensibility in both groups of patients.

Angina Pectoris↗
PubMed1996

Prospective studies on left ventricular geometric patterns and exercise tolerance in unmedicated men with borderline and mild hypertension.

OBJECTIVE: This study was designed and conducted to assess the clinical significance of left ventricular geometric patterns and physical fitness in subjects with untreated borderline and mild hypertension. METHODS: Symptom-limited maximal treadmill stress testings and echocardiographic examinations were administered to 192 previously unmedicated men. Left ventricular geometric patterns were determined by the combined criteria of left ventricular mass index and relative wall thickness. Subjects whose left ventricular mass index was < 125 g/m2 were followed up for more than 3 years. RESULTS: Normalized treadmill time was lower and pressure rate products at peak exercise were higher in patients with concentric hypertrophy than in those with normal geometry. Of the 77 patients who revealed left ventricular mass index at baseline < 125 g/m2 and who were successfully followed without medication for more than 3 years, 18 demonstrated concentric hypertrophy at the final follow-up examination. During the follow-up period, these 18 patients had significant further augmentation of concentric geometric features, significant decreases in both cardiac output and normalized treadmill time, and significant increases in casual blood pressure and total peripheral resistance compared with those at baseline. CONCLUSION: Patients with concentric hypertrophy exhibited slightly but significantly impaired levels of physical fitness and cardiac work efficiency, and the progression of concentric hypertrophy demonstrated further impairments of these conditions. Therefore, not only lowering blood pressure, but also improving left ventricular hypertrophy, cardiovascular hemodynamics, and physical fitness might be required in patients with concentric hypertrophy.

Adult↗
PubMed1996

Left ventricular hypertrophy in mild essential hypertension. Its progression, prediction and treatment strategy.

Since the pathogenesis of left ventricular hypertrophy (LVH) in hypertension is thought to be multifactorial, the antihypertensive strategy also has to be multifaceted. Diagnosis of LVH is more reliable than ever with echocardiography either of the M-mode or 2D method. Diagnostic criteria have already been proposed by Ganau et al who classified LV morphology into 4 different sectors based on the standard values of left ventricular mass index (LVMI) and relative wall thickness in diastole (RWTd); normal, concentric remodeling, concentric hypertrophy and eccentric hypertrophy. The concentric hypertrophy pattern is the most risky with regard to prognosis. Therefore, its detection and prediction for further progression have to be conducted with relatively easy routine work-up procedures such as echocardiography and maximal exercise testing. The prediction of LVH progression has already been proposed based on several studies conducted in patients with borderline or mild hypertension. The following two predictors were defined as LVMI > 124 g/m2 and peak Ps at maximal exercise testing > 200 mmHg. Therefore, the patient who meets these criteria has to be treated with medications that are appropriately selected on an individualized basis. Both hyperinsulinemia and insulin resistance are thought to be involved in the initiation, promotion and potentiation of remodeling of the LV in hypertension. Physical fitness also seems to be decreased in a parallel manner. Selection of the most appropriate drug for a given patient has to be individually determined based on the risks that have to be corrected. Finally, arteriosclerosis, which is almost always initiated and progresses in concert with hypertension, must also be targeted with regard to such prognostic aspects as cardiovascular morbidity and mortality. Arteriosclerosis is pathogenetically independent from hypertension, but usually behaves in concert with it. Selection of medication must be focussed on an individualized basis not only for LVH, but also for improvement in arterial elasticity. Further clinical research is still needed to provide more reasonable approaches to patients with hypertension.

Angiotensin II↗
PubMed1996

[Advancement of management of arrhythmias associated with exercise testing].

Exercise-induced isolated premature contractions occur in healthy subjects, as well as in patients with cardiac disease. On the other hand, the prevalence of exercise-induced supraventricular or ventricular tachycardia is uncommon among most healthy subjects in usual clinical laboratory settings. Significant coronary heart disease may be found in patients who reveals ventricular arrhythmias during the phase of graded exercise testing. The absence of increase of heart rate during submaximal exercise usually suggests sinus node dysfunction. Exercise testing is of value when it comes to assessing the site of AV block in patients with atrioventricular (AV) block. Exercise testing is also useful to clarify arrhythmic implications for various exercise-related complaints and may help to assess risk strafication and effects of interventions. The clinical significance of induction or suppression of arrhythmia during exercise still remains to be investigated.

Arrhythmias, Cardiac↗
PubMed1996

Safety and effectiveness of exercise training in patients with silent myocardial ischemia.

The effectiveness of exercise training in patients with silent myocardial ischemia was examined. Forty patients with coronary heart disease (mean age 55 +/- 8 years) were recruited for a 12-week exercise training program. All patients underwent treadmill exercise stress testing, exercise thallium-201 single photon emission computed tomography and left heart catheterization. They were divided into three groups based on the symptoms and the results of exercise thallium scintigraphy, i.e., painful myocardial ischemia (PMI group), silent myocardial ischemia (SMI group), and non-myocardial ischemia (NMI group). Normalized treadmill time was longer in the SMI group (108 +/- 24%) than in the PMI group (86 +/- 14%, p < 0.05). All 40 patients, 14 from the PMI group, 16 from the SMI group and 10 from the NMI group, completed the whole exercise training program. A significant prolongation of treadmill time was attained in all three groups after exercise training [PMI group: from 494 +/- 105 to 632 +/- 78 sec (p < 0.05), SMI group: from 609 +/- 147 to 746 +/- 137 sec (p < 0.05), NMI group: from 572 +/- 112 to 739 +/- 13 sec (p < 0.05)]. The improvement of myocardial ischemia following exercise training was similar in the SMI and PMI groups. No adverse effects were detected throughout the program. The exercise training program adopted in this study proved safe and effective in patients with silent myocardial ischemia.

Adult↗
PubMed1993

[Respiratory changes in the blood flow pattern of the superior vena cava in patients with chronic obstructive pulmonary diseases].

Blood flow patterns in the superior vena cava (SVC) obtained from 20 elderly cases of COPD (aged 60-81) were compared with those from 24 elderly normal subjects (aged 61-80). The peak flow velocity and duration of two major antegrade flows during systole and diastole (S & D wave) were both qualitatively and quantitatively assessed with pulsed Doppler echocardiography. While peak flow velocity and duration of the S and D waves increased during inspiration and decreased during expiration in normal subjects, respiratory variations of these antegrade waves were extremely greater in patients with COPD with augmented and/or fused antegrade waves during inspiration, and there decrease was associated with an upward shift above the zero level during expiration. The duration of the D wave was significantly longer in COPD patients than in normal subjects and also revealed a significantly positive correlation with FEV1.0%. These findings suggest that SVC flow pattern is useful for the assessment of early right ventricular dysfunction in patients with COPD, but further clinical studies are required to confirm this thesis.

Aged↗