Thrombolytic treatment and complement activation

Details of possible complement activation in acute myocardial infarction (AMI) and the in vivo effects of fibrinolytic agents on this activation are not yet known. We measured complement activation in 40 patients with AMI: 20 were treated with streptokinase, and 20 did not receive any fibrinolytic agent. Anaphylatoxin C4a, C3a and membrane attack complexes SC5b-9 increased about 10-fold (p < 0.0001) during streptokinase infusion. There were no increases in complement catabolic products in AMI patients not treated with streptokinase. Significant transient leukopenia (-29.5%, 7.0 SEM, p = 0.001) and a drop in systolic pressure (-29%, 3.4 SEM, p < 0.0001) occurred after 15 min of streptokinase infusion simultaneously with the peak of anaphylatoxins in plasma.

Left ventricular diastolic function in normotensive adolescents with different genetic risk of hypertension

Abnormalities of the diastolic function of the left ventricle are the first sign of cardiac involvement in arterial hypertension. We have studied the diastolic function in a group of normotensive adolescents with confirmed family history of hypertension. M-mode echocardiography was performed in 86 normotensive males aged 14-19 years: 41 sons of at least one hypertensive parent (SHT) and 45 sons of normotensive parents (SNT). Cross-sectional area of the left ventricle and left ventricular (LV) mass index were significantly greater in the SHT than in the SNT group (10.05 +/- 1.84 vs. 8.9 +/- 1.56 cm/m2, p less than 0.01 and 129.3 +/- 296.3 vs. 109.23 +/- 25.7 g/m2, p less than 0.002, respectively). No significant difference between the two groups was observed in the indices of left ventricular diastolic function, except for mitral valve opening rate (463.51 +/- 90.45 in SHT vs. 416.71 +/- 78.84 mm/s in SNT; p less than 0.02). From the analysis of the subgroup of adolescents having left ventricular mass greater than the upper normal value, we observed that they showed mean time of rapid filling significantly longer than SNT: this could represent an early marker of the pathological character of such hypertrophy. Our results suggest that the higher LV mass observed in the SHT is not associated with chamber and myocardial stiffness abnormalities.

[Relations between pressure overload and early signs of cardiac involvement in arterial hypertension]

In arterial hypertension the indexes of left ventricular hypertrophy are not related to resting blood pressure, whereas a positive association with exercise blood pressure has been observed. It has not been investigated a possible relationship between response to stress and left ventricular diastolic function, the latter being early involved in arterial hypertension even before the development of ventricular hypertrophy. The present study was aimed at assessing a possible relationship between blood pressure response to dynamic exercise and index of left ventricular mass, systolic and diastolic function in a group of untreated hypertensives. fourty hypertensives aged 16-56 years were studied, 27 with mild hypertension and 13 with moderate or severe hypertension. The control group consisted of 23 normotensive healthy subjects, aged 14-40 years. All the subjects underwent a maximum-graded bicycle exercise in the supine position and a M-mode echocardiogram under the B-mode drive. Average values of the indexes of ventricular hypertrophy and of systolic function were overlapping in the 3 groups. Significant differences were observed in the indexes of diastolic function; with regard to normatensive controls, hypertensive subjects showed an increase in isovolumic relaxation time and rapid filling time, a decrease of isovolumic and rapid filling rates and a reduction of mitral valve closing and opening velocities.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of ventricular function in arterial hypertension with radionuclide ventriculography

Diastolic function of the left ventricle was assessed in 29 untreated patients with mild to moderate hypertension and in 21 normotensive control subjects using gated radionuclide ventriculography. In hypertensive patients, the time to peak filling rate was significantly longer (p less than 0.01) than that in control subjects, and first-third filling fraction and peak filling rate were significantly reduced (p less than 0.001). The ejection fraction and peak ejection rate were also significantly reduced in hypertensive patients (p less than 0.001). No relation was observed between diastolic functional impairment and age, cardiac hypertrophy, or severity of hypertension. Thus, early impairment of ventricular filling is present in hypertension, even in young patients without evidence of cardiac hypertrophy.

Arm position as a source of error in blood pressure measurement

The present study was designed to assess the value of correct positioning of a patient's arm when measuring blood pressure (BP). A total of 181 subjects were examined, 141 hypertensives on treatment, 25 untreated hypertensives, 15 normotensives. All the subjects underwent three BP measurements after a 5-min resting period in supine position. Then two BP readings were recorded in standing position with the arm either positioned by the patient's side or supported passively at patient's heart level. Average systolic BP (SBP) in standing position were 144.6 +/- 20.2 mmHg with the arm at the side and 136.4 +/- 21.1 mmHg with the arm at the heart level (p less than 0.001); average diastolic pressures were 99.0 +/- 12.0 mmHg and 90.2 +/- 12.3 mmHg (p less than 0.001), respectively. A fall in SBP greater than or equal to 20 mmHg from the supine to the upright position was detected in 18.2% of cases when measurement was performed at heart level; such a reduction was inapparent in two-thirds of cases when the arm was placed at the patient's body side. Incorrect positioning of a patient's arm during BP measurements in standing position leads to overestimation of BP values and masks the presence of postural hypotension.

[Usefulness of exertion tests in the evaluation of the effectiveness of antihypertensive therapy]

Aim of this study was to assess the reliability of blood pressure (BP) response to exercise compared with the occasional BP measurements in evaluating the efficacy of an antihypertensive therapy. We have studied 40 subjects (22 M, 18 F mean age 33.3 +/- 6.6) with essential hypertension (19 with mild hypertension, 8 with moderate hypertension, 13 with severe hypertension). Every patient underwent a maximum graded exercise test in the supine position on a bicycle ergometer before starting the antihypertensive treatment. An exercise test was repeated with the same procedure after resting BP had been normalized for at least six months. Both systolic and diastolic BP at peak exercise were significantly reduced (systolic BP from 212.13 +/- 25.79 mmHg to 194.38 +/- 21.58 mmHg; diastolic BP from 128.00 +/- 16.52 to 114.1 +/- 11.02 mmHg) during the second test. An excessive BP increase (above the 95% confidence limits of the BP response to exercise in a group of normotensives) was observed in 32 subjects during the first test. A "hypertensive" response to stress persisted in 13 subjects during the second test even if the resting BP values were normalized. Our data support the value of stress testing in both the evaluation of the hypertensive patient and the assessment of the individual response to treatment.