Effects of acute K-strophantidin administration on left ventricular relaxation and filling phase in coronary artery disease.

In 10 patients with coronary artery disease, preserved left ventricular (LV) performance and absence of previous myocardial infarction, the effects of an acute intravenous administration of k-strophantidin (0.005 mg/kg over 10 minutes) on selected parameters of both LV systolic and diastolic function, including relaxation, were evaluated. An increase in positive first derivative of LV pressure (dP/dt) and in the ratio between dP/dt and the pressure developed (dP/dt/P) (1,530 +/- 287) 1,600 +/- 329 mm Hg/s [p less than 0.05], and 30 +/- 6 to 34 +/- 8 s-1 [p less than 0.05], respectively) demonstrated the inotropic effect of k-strophantidin, whereas volumetric parameters of systolic function (end-systolic and stroke volume indexes, and ejection fraction) did not show any significant change. However, LV relaxation was impaired by k-strophantidin injection; in fact, mean values of T constant were significantly increased from 50 +/- 12 to 55 +/- 13 ms (p less than 0.01). Lowest LV and end-diastolic pressures increased from 8 +/- 4 to 11 +/- 4 mm Hg (p less than 0.05) and from 17 +/- 6 to 20 +/- 8 mm Hg (p less than 0.05), respectively. The end-diastolic volume and maximal rate of volumetric increase during the early and late filling phases were not modified by k-strophantidin. Mean aortic pressure increased from 110 +/- 10 to 120 +/- 12 mm Hg (p less than 0.001). Therefore, in patients with coronary artery disease and LV preserved performance, an acute intravenous administration of k-strophantidin appears to stimulate contractility and to worsen relaxation, and minimal LV and end-diastolic pressures.

Detection of early abnormalities of left ventricular function by hemodynamic, echo-tissue Doppler imaging, and mitral Doppler flow techniques in patients with coronary artery disease and normal ejection fraction.

We have investigated the possibility of detecting early abnormalities of left ventricular function at the initial phase of ischemic cardiomyopathy. Sixteen normotensive patients with coronary artery disease and normal left ventricular ejection fraction and 6 control patients were studied by invasive hemodynamic techniques in combination with transmitral Doppler flow or with echo-tissue Doppler imaging. The extent of the percentage of left ventricular longitudinal shortening and the systolic peak velocity at echo-tissue Doppler were significantly higher in the control patients than in patients with ischemic cardiomyopathy (P <.01). Left ventricular end-diastolic pressure was higher (P <.05), whereas mean values of isovolumic contraction and relaxation indexes (dP/dt/P: P <.05; +dP/dt: P <.05; -dP/dt: P <.01) were lower in patients with ischemic cardiomyopathy. Tau was significantly longer in ischemic patients (42.7 +/- 8.8 versus 34.5 +/- 3.7 ms, P <.05). In the control patients, the aortic valve closure to peak E interval by transmitral Doppler flow was significantly longer than that measured by echo-tissue Doppler (P <.001), whereas in patients with ischemic cardiomyopathy, this interval difference was still present and significantly shorter (P <.05). In patients with coronary artery disease and normal ejection fraction, minor and early abnormalities of left ventricular function related to isovolumic contraction and relaxation as well as to longitudinal shortening could be detected. In addition, a suction-like effect, detected during early filling evaluation with echo-tissue Doppler, is significantly decreased but not abolished during the early stages of coronary artery disease.

Long non-iatrogenic right coronary artery dissection in stable angina pectoris treated with stenting.

An extensive spontaneous right coronary artery dissection was the only abnormal angiographic finding detected in a 67-year-old man with chronic exercise-induced angina pectoris. The lesion was treated with multiple stenting with good angiographic results. The clinical implications of this finding and the details of the intervention performed are discussed in light of published data concerning this increasingly recognized angiographic entity.

Do inotropic drugs always induce a positive lusitropic effect? A comparison between k-strophanthidin and dobutamine in patients with coronary artery disease.

The interaction between systolic and diastolic effects of inotropic drugs is an important subject which has not yet been fully clarified in the cardiological literature. The effects of the inotropic drugs k-strophanthidin and dobutamine on left ventricular (LV) relaxation and early filling phase were compared in patients with coronary artery disease (CAD) and preserved systolic function. Twenty-two patients were randomly divided into two groups; group I was infused with 0.0035 mg.kg-1 of k-strophanthidin for 10 min and group II with dobutamine at a rate of 10 micrograms.kg-1.min-1 for 10 min. Both groups underwent simultaneous haemodynamic and echo 2D-Doppler evaluations at controlled heart rate. K-strophanthidin improved contractility indexes (peak of LV systolic pressure P < 0.001, max dP/dt + P < 0.05 and dP/dt P < 0.01) and worsened T constant and LV lowest diastolic pressure, (LVLDP) (P < 0.001 and P < 0.05 respectively) without changing early transmitral filling parameters. Dobutamine induced a significant increase in contractility in group II but at the same time significantly improved LV relaxation variables (max dP/dt - P < 0.01 and T constant P < 0.001). In addition, dobutamine reduced LVLDP (P < 0.05) and significantly increased LV early filling parameters. These results show that an acute administration of either k-strophanthidin or dobutamine enhances contractility, whereas these drugs have the opposite effect on the early diastolic phase.

[Effects of Prenalterol on left ventricular function of coronary patients]. / Effetti del prenalterolo sulla funzione ventricolare sinistra del coronaropatico.

The aim of the study was to assess the effect of Prenalterol on cardiovascular beta adrenergic system of 12 coronary artery disease patients with a previous myocardial infarction. For this purpose, left ventricular function was assessed before and after intravenous administration of 30 gamma/Kg of Prenalterol, under a constant heart rate, provided by atrial pacing. Prenalterol induced a significant improvement of left ventricular contractility (dp/dt pos.-VCEmax-Vmax d), relaxation (dp/dt neg.-T constant), ventricular compliance (total diastolic compliance-modulus of chamber stiffness-end-diastolic compliance) and pump (ejection fraction) indices. These results suggest the potential usefulness of Prenalterol in severe acute cardiac failure.

Effect of dobutamine on left ventricular relaxation and filling phase in patients with ischemic heart disease and preserved systolic function.

The beneficial effects of dobutamine on left ventricular systolic and diastolic phases have been described in patients with congestive heart failure. Its influence on left ventricular diastolic phase in patients with preserved systolic function, absence of dys- or akinetic areas, and left ventricular dilatation has not yet been adequately investigated. Thus a simultaneous echo-Doppler and hemodynamic study was performed in 15 patients with ischemic heart disease and preserved systolic function in order to assess the effect of dobutamine on left ventricular relaxation and filling phase. The infusion of dobutamine at a rate of 10 micrograms/kg/min induced a marked inotropic action, as shown by the significant increase in positive dP/dt (from 1392 +/- 224 to 2192 +/- 295 mmHg/sec, p < 0.001), dP/dt/P (from 32 +/- 8.1 to 50 +/- 17 sec-1; p < 0.0001), and in peak of systolic pressure (from 143 +/- 25 to 168 +/- 36 mmHg; p < 0.005). In addition, dobutamine reduced the end-systolic volume index (from 30 +/- 16 to 26 +/- 19 ml/m2; p < 0.05), the end-systolic stress (from 222.2 +/- 65.3 to 198.4 +/- 84 g/cm2; p < 0.006), and had favorable effects on relaxation and the early filling phase.(ABSTRACT TRUNCATED AT 250 WORDS)

[Early changes in ventricular function in diastolic phase in the resting coronary patient]. / Precoci alterazioni della funzione ventricolare in fase diastolica nel coronaropatico a riposo.

The aim of this study is to test left ventricular diastolic function in coronary artery disease patients with preserved systolic performance. Two groups of patients (25 coronary artery disease patients with angiographic proved coronary artery stenosis, but with normal hemodynamic and angiographic indices of systolic phase, first group; and 14 normal subjects for control, second group) were tested comparing their systolic and diastolic ventricular function indices, obtained by using a Millar microtip catheter and a computerized program. Systolic ventricular function was similar in the two groups (EF: 0.61 +/- 0.05 vs 0.62 +/- 0.03, p: n.s.; Vmax:120 +/- 28 vs 112 +/- 24 sec-1, p: n.s.), while diastolic indices were significantly different (lowest diastolic pressure: 3.7 +/- 2.4 vs -1.72 +/- 1.45 mmHg, p less than 0.01; end-diastolic pressure: 11.2 +/- 4.2 vs 6.5 +/- 2.8 mmHg, p less than 0.05; T constant: 45 +/- 8 vs 35 +/- 6 mmHg, p less than 0.001; end-diastolic compliance: 2.79 +/- 0.3 X 10(-2) vs 5.68 +/- 0.4 X 10(-2) mmHg-1, p less than 0.001; Kp: 0.041 +/- 0.006 vs 0.003 +/- 0.004 p less than 0.001). In conclusion, impairment of left ventricular diastolic phase may be one of the earliest manifestations of functional alterations of ischemic ventricle.