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Biomedical subjects

I Wallentin

Publications and source records attributed to I Wallentin.

At least 73 records · Page 4Linked to original sources
PubMed1976

Plasma renin activity and hypertensive organ manifestations in 50-year-old males.

From a screening examination in a randomly selected third of the 50-year-old male population in Göteborg, Sweden, a 10% subsample was selected as a reference group (n=80). All untreated persons with SBP greater than 175 or DBP greater than 115 mmHg on two separate occasions made up the hypertension group (n=35). The reference group and the hypertension group were subjected to the same investigations, including BP measurement before and after rest and determination of plasma renin activity (PRA), urinary sodium and norepinephrine excretion and GFR. Plasma renin activity was approximately normally distributed in both the reference and the hypertension group. Mean values were 0.78 +/- 0.18 and 0.65 +/- 0.17 ng/ml/h respectively, the difference being almost statistically significant (0.10 greater than p greater than 0.05). There was no difference with respect to sodium excretion between the reference group and the hypertension group. In the reference group, heart rate was positively correlated to PRA and to urinary norepinephrine excretion during the day. No linear correlation between PAR and BP was found, either in the reference group, or in the hypertension group. Sodium excretion during the day was positively correlated to GFR in the hypertension group, but not in the reference group. Compared to hypertensives with normal or high sodium excretion during the day, the hypertensives with low sodium excretion during the day were characterized by a higher BP, a lower GFR and a reversed diurnal rhythm of urine excretion. Thus, low sodium excretion seemed to indicate more severe hypertension with increased renal resistance during the day. The hypertension group was also divided with regard to sodium excretion into a low, normal and high renin group. The low renin group had the lowest GFR and with rising renin group (from low via normal to high) there was a significant increase in GFR and a significant decrease in resting BP. The results indicate that low renin hypertension is not a more mild, but indeed rather a more severe form of hypertension.

Blood Pressure↗
PubMed1976

Non-invasive assessment of the heart in the hypertensive.

The prevalence of signs of heart involvement was studied non-invasively with orthogonal and conventional ECG, apexcardiogram, carotid pulse tracing and phonocardiogram in a group of untreated hypertensives (n = 35) and a reference group (n = 73). All were derived by screening a random population sample of 50-year-old men.

Animals↗
PubMed1976

Orthogonal electrocardiogram, apex cardiogram, and atrial sound in normotensive and hypertensive 50-year-old men.

The prevalence of signs of heart involvement was studied non-invasively in a group of untreated hypertensives (n=35) and a reference group (n=73), all derived from a random population sample of 50-year-old men. Signs of left ventricular hypertrophy were studied by means of orthogonal electrocardiography and conventional electrocardiography. Signs of decreased distensibility of the left ventricle were studied by apex cardiography and registration of atrial sounds. Left ventricular hypertrophy among hypertensives was significantly more common according to orthogonal electrocardiography (33%) than according to conventional electrocardiography (9%), indicating that the former may be a better method for detection of left ventricular hypertrophy than the latter. In the hypertension group the amplitude of the R wave in lead X on orthogonal electrocardiography was positively correlated to casual diastolic blood pressure (r=0-40) and to diastolic blood pressure after one hour's rest (r=0-65). The degree of pressure load leading to left ventricular hypertrophy seems to be better reflected by resting than by casual blood pressure. There was no hypertensive subject with both signs of left ventricular hypertrophy on orthogonal electrocardiography and either an a/H ratio over 15 per cent or an abnormal atrial sound, indicating two different forms of cardiac involvement as the result of hypertension. Casual blood pressures became normal during rest in hypertensives with a/H ratio over 15 per cent on apex cardiography or abnormal atrial sound, not in hypertensives with signs of left ventricular hypertrophy on orthogonal electrocardiography.

Blood Pressure↗
PubMed1976

Multiple arterial occlusions and hypertension probably caused by an oral contraceptive: a patient in whom the development of renovascular hypertension has been followed.

An 18-year-old woman taking an oral contraceptive was admitted to hospital because of a stroke due to occlusion of three branches of the right middle cerebral artery. She later developed renovascular hypertension due to occlusion of one of two renal arteries on the right side. Occlusion of the ceoliac artery was also found. The circumstances suggest that the occlusions were caused by multiple emboli, the source of which could not be identified. The kidney with the circulatory disturbance was shown to have a persistent abnormal renin secretion three and six months after the stroke, but the peripheral renin level was lower at the second investigation. Cardiac function studies revealed an alarming degree of left ventricular hypertrophy, and satisfactory blood pressure control could not be maintained despite increasing antihypertensive therapy. Surgical corrrction of the circulatory disturbance promptly led to normotension without drugs, and the patient has remained normotensive during the postoperative observation period of twelve months. The oral contraceptive was probably responsible for precipitating the vascular occlusions, but no predisposing factors or warning symptoms were present to identify this patient as being at risk.

Adolescent↗
PubMed1975

Effect of chronic beta-adrenergic receptor blockade in congestive cardiomyopathy.

Adrenergic beta-blocking agents were given to 7 patients with advanced congestive cardiomyopathy who had tachycardia at rest (98 plus or minus 13 beats/min). The patients were on beta-adrenergic receptor blockade for 2 to 12 months (average 5-4 months). One patient was given alprenolol 50 mg twice daily and the other patients were given practolol 50 to 400 mg twice daily. Virus infection had occurred in 6 of the patients before the onset of symptoms of cardiac disease. All patients were in a steady state or were progressively deteriorating at the start of beta-adrenergic receptor blockade. Conventional treatment with digitalis and diuretics was unaltered or reduced during treatment with beta-blocking agents. An improvement was seen in their clinical condition shortly after administration of the drugs. Continued treatment resulted in an increase in physical working capacity and a reduction of heart size. Noninvasive investigations including phonocardiogram, carotid pulse curve, apex cardiogram, and echocardiogram showed improved ventricular function in all cases. The present study indicates that adrenergic beta-blocking agents can improve heart function in at lease some patients with congestive cardiomyopathy. Furthermore, it is suggested that increased catecholamine activity may be an important factor for the development of this disease, as has been shown in animal experiments.

Adult↗
PubMedDate not supplied

Diastolic function of the heart in untreated primary hypertension.

To study left ventricular (LV) diastolic function of the heart in relation to blood pressure (BP) and other signs of hypertensive cardiac and peripheral vascular changes, isovolumic relaxation time and early diastolic filling were determined in four BP groups of untreated 49-year-old men: normotensive subjects (n = 20), men with borderline hypertension (n = 30), mild hypertension (n = 45), and moderate to severe hypertension (n = 24). Isovolumic relaxation time, measured as the distance between aortic closure (A2, phonocardiography) and mitral valve opening (echocardiography), and early diastolic filling, measured as the distance between mitral valve opening and the O point of the apexcardiogram, tended to increase with BP level, and the total interval from aortic closure to the O point (A2O interval) was significantly prolonged in the two groups with mild and moderate to severe hypertension. A prolonged A2O interval (greater than or equal to 117% of expected value at observed heart rate) was seen in several hypertensives, who had no obvious increase in LV wall thickness on M mode echocardiography. This suggests that a prolonged LV relaxation time may be an early sign of cardiac involvement in primary hypertension. In the group with moderate to severe hypertension, an increase in LV wall thickness was seen together with an increase in resistance at maximal dilation in the calf. This supports the theory that when changes in cardiac structure develop they occur in parallel with structural changes also in the periphery.

Blood Pressure↗
PubMedDate not supplied

Left ventricular wall stress and systolic function in untreated primary hypertension.

A noninvasive investigation was undertaken in four blood pressure (BP) groups of untreated 49-year-old men derived by screening a random population sample: normotensive men (n = 20) and subjects with borderline (n = 30), mild (n = 45), or moderate BP elevation (n = 24). We here report the findings regarding left ventricular (LV) wall stress, LV wall thickness, and LV systolic function. Although there was an increase in LV wall thickness with hypertension, the raised BP was not compensated for by a sufficient degree of LV wall thickening to keep wall stress within normal limits in the hypertensive groups. Among a subset of individuals with pronounced increase in wall thickness peak systolic wall stress approached the normal range, but end-systolic wall stress was still high. In spite of high wall stress LV systolic function was normal or supranormal in the hypertensive men. The LV ejection phase indices showed a close inverse correlation with end-systolic wall stress (r = -0.67 to -0.84) in all four BP groups, but no correlation or only a weak correlation with peak systolic wall stress (r = 0.18 to -0.40). As judged from the relationship between end-systolic wall stress and ejection phase indices of LV function in the normotensive controls, all hypertensive groups had higher than expected values for LV ejection phase indices, which indicates an increased myocardial contractility secondary to adrenergic stimulation or to a more efficient contractile machinery in the myocardial cells.

Echocardiography↗