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Biomedical subjects

M Ikäheimo

Publications and source records attributed to M Ikäheimo.

At least 19 recordsLinked to original sources
PubMed1992

Which anti-hypertensive to add to a beta-blocker: ACE inhibitor or diuretic?

Thirty-eight patients already treated with atenolol 50 mg once daily were randomly assigned to treatment with either hydrochlorothiazide (12.5-25 mg once daily) or lisinopril (10-20 mg once daily) for 8 weeks in a double-blind crossover study. Eight weeks' treatment with the combination of ACE inhibitor and beta-blocker or the diuretic and beta-blocker produced falls in blood pressure (lying: -8.4 +/- 15.4/ -7.3 +/- 80 mmHg and -6.1 +/- 15.3/ -5.2 +/- 8.8 mmHg [mean +/- SD] for lisinopril and hydrochlorothiazide respectively; standing: -10.2 +/- 14.2/8.2 +/- 9.2 mmHg and -6.8 +/- 14/ -6.3 +/- 10.3 mmHg for lisinopril and hydrochlorothiazide respectively) which were not statistically significantly different. Heart rate was significantly increased on the combination of beta-blocker and diuretic (lying: +4.3 +/- 10.7; standing: +3.2 +/- 10.0 beats/min) compared with a fall on beta-blocker+ACE inhibitor (lying; -0.5 +/- 7.6; standing: -1.5 +/- 7.4). Both therapeutic regimens were equally well tolerated. These results suggest that where patients fail to respond to monotherapy with a beta-blocker the addition of an ACE inhibitor may be as effective as the more traditional option of diuretic therapy.

Adolescent↗
PubMed1991

Changes in myocardial energy metabolism in elective coronary angioplasty.

STUDY OBJECTIVE: The aim was to investigate the effect of coronary angioplasty on myocardial energy metabolism, and to assure the safety of the procedure in patients with coronary heart disease. DESIGN: Before angioplasty a catheter was introduced into the coronary sinus. Blood samples were taken simultaneously from femoral artery and coronary sinus before balloon inflation, upon balloon deflation, and two minutes later, and arteriovenous differences in myocardial substrates, pH, PCO2, oxygen saturation, and adenosine catabolites were determined. PATIENTS: 14 patients with angiographically documented coronary artery disease with lesions in the left coronary artery suitable for elective coronary angioplasty were included in the study. RESULTS: During balloon inflation the positive femoroarterial-coronary sinus difference of lactate turned negative, from 0.21(SEM 0.05) mM to -0.10(0.11)mM, p less than 0.02. At the same time pH and PCO2 differences increased: from 0.04(0.00) U to 0.07(0.01) U, p less than 0.01, and from -1.15(0.10) kPa to -1.41(0.10) kPa, p less than 0.01, respectively. The changes were, however, transient and the arteriovenous differences in these metabolic variables rapidly returned towards preinflation levels after balloon deflation. The femoroarterial-coronary sinus concentration differences in glucose and free fatty acids became positive in coronary angioplasty. The energy state remained good during the procedure as assessed from the negligible net efflux of adenosine and its degradation products. CONCLUSIONS: Elective coronary angioplasty can be performed without any persistent derangements in myocardial metabolism, and may in fact lead to improvement of utilisation of some myocardial substrates. Lactate appears to be a more sensitive indicator of short term ischaemia than adenosine degradation products.

Adenosine↗
PubMed1990

Isometric exercise testing and echocardiography at rest in aortic valve incompetence.

Thirty patients with aortic valve incompetence and 21 control subjects were examined by M-mode echocardiography at rest and radionuclide ventriculography during submaximal handgrip exercise. The patients had greater left ventricular dimensions and end-systolic wall stress values but peak systolic wall stress values did not differ. During exercise the controls' ejection fraction increased by 3 +/- 4%, 95% confidence interval (CI) from +1% to +5%, while the aortic incompetence patients showed no change -1% +/- 5%, CI from -3 to +1%. The 15 symptomatic aortic incompetence patients had a different ejection fraction response from the controls (-2 +/- 4%, p less than 0.01), CI from 4% to +1%, but the 15 asymptomatic patients had not (0 +/- 6%, not significant, CI from -3% to +3%). Three symptomatic and two asymptomatic patients with a decrease in ejection fraction below 5% during handgrip were not identified by left ventricular size and function of systolic loading conditions at rest. Neither echocardiographic or radionuclide parameters of left ventricular size and function at rest correlated with the individual ejection fraction changes during handgrip. Thus, in aortic valve incompetence, the radionuclide angiography assessed functional response to handgrip cannot be predicted by left ventricular size and function or systolic loading conditions at rest.

Adult↗
PubMed1989

Left ventricular dimensions during isometric exercise in aortic valve incompetence assessed by M-mode echocardiography and gated equilibrium radionuclide angiography.

We compared M-mode echocardiographic and gated equilibrium radionuclide angiography assessment of the left ventricular (LV) dimensions at rest and during isometric exercise in 18 patients with chronic aortic valve incompetence. The two methods showed a satisfactory correlation when comparing LV size at rest and during exercise (LV end-diastolic dimension in echocardiography vs LV end-diastolic volume in radionuclide angiography, r = 0.80, P less than 0.01 at rest and r = 0.81, P less than 0.01 at rest and r = 0.75; P less than 0.01 during exercise), but fractional shortening in echocardiography and ejection fraction in radionuclide angiography did not correlate (r = 0.27, not significant (NS) at rest and r = 0.34, NS during exercise). Thus echocardiography and radionuclide angiography describe LV dimensions at rest and during handgrip exercise in a similar fashion, documenting the concordance of these noninvasive methods to describe LV size in aortic incompetence at rest and during exercise.

Adult↗
PubMed1989

Abrupt change from a beta-adrenoceptor blocking drug to enalapril in hypertension.

The haemodynamic and hormonal effects of an elective change of antihypertensive therapy from a beta-adrenoceptor blocking drug to a converting enzyme inhibitor, enalapril, were monitored in 12 hypertensive in-patients (WHO I). Blood pressure and heart rate were determined every 2-4 h using an automatic sphygmomanometer during an abrupt cessation of the previous beta-adrenoceptor blocking drug and commencement of treatment with enalapril 20 mg o.d. 12 h later. Mean blood pressure values at rest and during the hand grip test were lower when on enalapril, but heart rate was significantly higher, and three patients suffered from palpitations during the change. The change resulted in an improvement in cardiac function both at rest and during isometric work, as shown by echocardiography. A rapid decrease in plasma angiotensin converting enzyme (ACE) activity and an increase in renin activity were also seen after the change, while plasma levels of atrial natriuretic peptide (ANP) decreased towards normal values. The results suggest that an abrupt change from a chronic beta-adrenoceptor blocking drug to enalapril is safe, feasible and is likely to produce favourable haemodynamic and hormonal effects in hypertensive patients.

Adrenergic beta-Antagonists↗
PubMed1988

Electrocardiographic criteria for the diagnosis of right ventricular hypertrophy verified at autopsy.

Four commonly used sets of electrocardiographic (ECG) criteria for diagnosing right ventricular hypertrophy (RVH) were tested for sensitivity and specificity in 12 men with isolated RVH, 15 with combined right and left ventricular hypertrophy and 24 with normal ventricular weights. The cardiac ventricles were weighed separately at autopsy and the left-to-right ratio was calculated. All the patients showing isolated RVH, with a left-to-right ratio of two or less, had died of respiratory causes. Three sets of ECG criteria showed a specificity of 100 percent, but sensitivities only from 26 to 44 percent. One set was more sensitive (74 percent) but much less specific than the others (79 percent). A new combination of ECG criteria attained a 63 percent sensitivity and a 96 percent specificity.

Adult↗
PubMed1987

Impaired left ventricular diastolic function in athletes after utterly strenuous prolonged exercise.

Digitized M mode echocardiography was used to evaluate the effect of a competitive 24-h run on the left ventricular diastolic function in 12 well-trained marathon runners who completed 146-227 km during the race. Mitral valve opening was delayed, early diastolic filling was decreased and prolonged, and posterior wall thinning was reduced, particularly among those athletes completing close to 200 km or more. Since the alterations were in part the opposite in those running 160 km or less, only the reductions in the peak rate of dimension increase (P less than 0.05) and posterior wall thinning (P less than 0.01) were significant in the group as a whole. The delay in mitral valve opening (r = 0.76), the decrease in the peak rate of dimension increase (r = -0.68), and the prolongation of the early diastolic filling period (r = 0.60) were correlated with the distance completed. The reductions in left ventricular end-diastolic dimension and fractional shortening were not in proportion to the distance run, however (r = 0.23 and 0.46, respectively). Measurements made on six athletes 2-3 days after the race showed reversal of the indices of left ventricular diastolic function. Extremely exhaustive prolonged exercise thus appears to result in a marked reversible impairment in left ventricular relaxation and filling. Since the effect of these abnormalities in cardiac filling during exercise is probably more important due to the shorter diastole, the prevention of hypohydration, which could otherwise further compromise left ventricular filling, becomes crucial.

Adult↗
PubMed1987

Comparison of echocardiographic and radionuclide methods with contrast angiography assessment of left ventricular function--response to isometric exercise in subjects without definite heart disease.

In order to study the validity of non-invasive assessment of left ventricular response to isometric exercise, 21 subjects with chest pain, but without any cardiac abnormalities performed an isometric handgrip test during cardiac catheterization, M-mode echocardiography and radionuclide angiography. Fourteen of the subjects were suitable for comparison of all the three methods. In response to handgrip exercise the ejection fraction (EF) remained unchanged in contrast angiography (68 +/- 9% at rest; 68 +/- 9% during exercise) and echocardiography (74 +/- 4% at rest; 74 +/- 5% during exercise), but showed a small increase on radionuclide angiography (from 57 +/- 5% to 60 +/- 7% (p less than 0.01). Individual changes in ejection fraction during the handgrip exercise had a reasonable correlation between contrast angiography and radionuclide angiography (r = 0.63, p less than 0.01). In order to validate the reproducibility of M-mode echocardiography and radionuclide angiography, the haemodynamic and left ventricular responses during two consecutive handgrip tests were compared in eight subjects. No significant differences were seen in the haemodynamic responses or between the changes in ejection fraction or fractional shortening in the two tests. Thus, in subjects without heart disease the non-invasively determined results of the left ventricular response to the handgrip exercise were similar to those obtained invasively and could be reliably reproduced.

Cardiac Catheterization↗
PubMed1985

Determination of the anaerobic threshold in the evaluation of functional status before and following valve replacement for aortic regurgitation.

The effect of aortic valve replacement on exercise capacity was evaluated in 28 patients with aortic regurgitation using repeat determinations of peak oxygen uptake (VO2) and the anaerobic threshold (AT), based on a nonlinear increase in the plot of pulmonary ventilation versus VO2. Although the AT was on average 68% of peak VO2 before and 1 year after surgery, the test-to-test correlation coefficient was 0.92 for the AT but only 0.68 for peak VO2 postoperatively. 11 patients (39%) improved in AT, usually within the first 6 months. The preoperative echocardiographic left ventricular end-diastolic dimension and its postoperative change correlated with that in the AT (r = 0.64 and -0.60, p less than 0.001) but not with that in peak VO2. The patients likely to improve had a lower AT (p less than 0.05) preoperatively, however. Thus repeat determinations of AT using respiratory measurements give additional data on changes in functional status. Sequential exercise testing does not require the patient to be exercised much past his AT.

Adult↗
PubMed1985

Haemodynamic effects of prazosin combinations during dynamic and isometric exercise.

Haemodynamic effects of atenolol 50 mg, clonidine 0.15 mg, and prazosin 5 mg, given twice daily, and of the combinations atenolol + prazosin and clonidine + prazosin were studied in 8 hypertensive outpatients. Measurements were made at rest, during isometric sustained handgrip and submaximal ergometer work in mostly double-blind and cross-over fashion. Given individually atenolol and prazosin lowered resting supine blood pressure. The addition of prazosin increased the antihypertensive effects of atenolol but not of clonidine. At the end of the isometric exercise atenolol and prazosin given alone both lowered diastolic blood pressure as compared to respective pretreatment values. During handgrip prazosin contributed a little, but not much, to the antihypertensive effects of atenolol and clonidine. During dynamic exercise atenolol, clonidine, and prazosin given alone each lowered blood pressure, prazosin decreasing diastolic blood pressure in particular. Prazosin added to the antihypertensive effect of atenolol more than that of clonidine. Echocardiographic measurements revealed no significant differences between treatments at rest. During handgrip the mean velocity of left ventricular circumferential muscle fibre shortening was reduced by atenolol as compared to pretreatment values. We conclude that atenolol + prazosin may help the patients to maintain adequate haemodynamics during daily physical stresses whilst the combination prazosin + clonidine may not offer any particular advantages.

Adult↗
PubMed1984

Impaired left ventricular filling in young female diabetics. An echocardiographic study.

To assess left ventricular (LV) function in diabetes mellitus, M-mode echocardiograms were recorded in 36 insulin-treated diabetic women, mean age 25 +/- 6 (SD) years, and 13 healthy women of the same age. Echocardiographic tracings of the septum and LV posterior wall were digitized and continuous plots were made of LV dimension and its rate of change. The pattern of LV filling was abnormal in 19 diabetics, when the mean value +/- 2 SD in the healthy women was taken as the normal range of the indices. The most common abnormality was a prolonged rapid filling period. The LV systolic function was normal in all diabetics. Diabetics with severe microvascular complications had thicker LV walls (p less than 0.05) and smaller LV end-diastolic diameters and stroke volumes (p less than 0.01) than the healthy women. The electrocardiographic voltage was lower in the diabetic group (p less than 0.05). These studies suggest that minor abnormalities in LV function reflecting stiffness of the myocardium are common in young female diabetics, a patient group with a relatively low prevalence of coronary artery disease.

Adolescent↗