Effects of unloading and positive inotropic interventions on left ventricular function in asymptomatic patients with chronic severe aortic insufficiency.

The effect of an unloading (nifedipine, 20 mg sublingually) and of a combined unloading and positive inotropic intervention (nifedipine plus digoxin, 0.5 mg intravenously) on left ventricular performance was assessed in 48 patients with chronic severe aortic insufficiency. The left ventricular pump function-myocardial contractility relation (ejection fraction, EF vs. peak arterial pressure to end-systolic volume ratio, PAP/ESV), and the pump function-afterload relation (EF vs. mean systolic wall stress, MWS) were constructed by means of quantitative M-mode and two-dimensional echocardiography. In patients with normal control pump function (n = 14), nifedipine markedly decreased MWS, moving the patients to a new, more advantageous EF-MWS relation. In the 34 patients with abnormal pump function, the myocardial contractility level was the mean factor conditioning the response to pharmacological intervention. Patients with a value of PAP/ESV greater than 2.5 (n = 22) had normalization of EF after nifedipine and were upgraded to a more advantageous outlook for left ventricular mechanics EF-MWS and EF-PAP/ESV relations. Of the 12 patients without normalization of EF after nifedipine, only the 4 patients with PAP/ESV greater than 2 had normalization of pump function indices after combined administration of nifedipine and digoxin

Long-term survival and functional results after aortic valve replacement in asymptomatic patients with chronic severe aortic regurgitation and left ventricular dysfunction

ObjectivesWe examined the influence of medical treatment on the results of surgery in terms of long-term survival and functional results in patients with chronic, severe aortic regurgitation (AR).BackgroundAsymptomatic patients with AR and a reduced left ventricular ejection fraction (LVEF) are at high risk because of a higher-than-expected long-term mortality. The influence of preoperative medical therapy on the outcome after aortic valve replacement (AVR) is not well known.MethodsSurgery was indicated for the appearance of a reduced LVEF (<50%). At the time of AVR, there were 134 patients treated with nifedipine (group A), and 132 received no medication (group B).ResultsOperative mortality was similar in the two groups (0.75% vs. 0.76%, p = NS). The LVEF normalized in all of group A, whereas it remained abnormal in 36 group B patients (28%). At 10-year follow-up, LVEF persisted higher in group A (62 ± 5% vs. 48 ± 4%, p < 0.001). Five-year survival was similar in the two groups (94 ± 2% vs. 94 ± 3%, p = NS). Group A showed a 10-year survival not different from expected and significantly higher than that in group B (85 ± 4% vs. 78 ± 5%, p < 0.001), which had a worse survival than expected.ConclusionsUnloading treatment with nifedipine in AR allows one to indicate AVR at the appearance of a reduced LVEF with a low operative mortality and an optimal long-term outcome. The concept of surgical correction of AR indicated for reduced LVEF may not be applied to all patients. Indeed, in a large amount of untreated patients, a reduced LVEF preoperatively is not reversed by prompt surgery, indicating irreversible myocardial damage, and 10-year survival is worse than expected

Myocardial dysfunction and abnormal left ventricular exercise response in autonomic diabetic patients

In diabetic patients, the pathophysiologic mechanisms of exercise-induced left ventricular (LV) dysfunction remain controversial. In this study, the role of myocardial contractility recruitment in determining an abnormal LV response to isometric or dynamic exercise has been investigated in 14 diabetic patients with autonomic dysfunction. Ischemic heart disease was excluded by the absence of LV wall motion abnormalities induced by isotonic and isometric exercise and by coronary angiography. Left ventricular and myocardial function were studied at rest, and during isometric and isotonic exercise, by two-dimensional echocardiography; moreover, recruitment of an inotropic reserve was assessed by postextrasystolic potentiation at rest and at peak handgrip. An abnormal response of LV ejection fraction to isometric (9/14) or to dynamic (8/14) exercise was frequent in study patients. In these patients, baseline myocardial contractility was normal, and the significant increase in ejection fraction by postextrasystolic potentiation indicated a normal contractile reserve (65 +/- 7% vs. 74 +/- 6%, p = 0.001). Nevertheless, the downward displacement of LV ejection fraction-systolic wall stress relationships during exercise suggests an inadequate increase in myocardial contractility. However, the abnormal ejection fraction at peak handgrip was completely reversed by postextrasystolic potentiation (67 +/- 6% vs. 58.1 +/- 10%, p = 0.008), a potent inotropic stimulation independent of the integrity of adrenergic cardiac receptors. A defective inotropic recruitment, despite the presence of a normal LV contractile reserve, plays an important role in deexercise LV dysfunction in diabetic patients with autonomic neuropathy

HEART-RATE-VARIABILITY IN PATIENTS WITH ORTHOTOPIC HEART-TRANSPLANTATION - LONG-TERM FOLLOW-UP

To evaluate heart rate variability (expressed as the standard deviation of RR intervals) within 5 years of follow-up, we studied 20 patients (14 males, 6 females, mean age 44 +/- 12 years) who underwent orthotopic heart transplantation. Six measurements were taken: one in the first 3 weeks after transplantation, and the others once annually, for 5 years. Twenty healthy subjects (mean age 44 +/- 7 years) constituted the control group. Heart rate variability increased significantly in the first 3 years of follow-up (7.2 +/- 1 vs. 11.1 +/- 4, p0.001; 11.1 +/- 4 vs. 15.2 +/- 4, p0.01; 15.2 +/- 4 vs. 18.9 +/- 5, p0.05); in the following years this trend slackened and values did not reach a statistically significant difference (18.9 +/- 5 vs. 21.4 +/- 5; 21.4 +/- 5 vs. 22.5 +/- 5). The mean standard deviation was invariably greater in the control group (63.6 +/- 12). These findings show that sinus rhythm variability in the denervated heart progressively increased over 5 years of follow-up. The absence of presynaptic uptake, which is responsible for adrenergic hypersensitivity to circulating catecholamines and intrinsic cardiac reflexes, does not appear to cause this phenomenon, since these mechanisms are not able to evolve in time after cardiac transplantation. Therefore, an enhanced beta-adrenergic receptors density or affinity to circulating catecholamines or a limited sympathetic reinnervation may be the more probable underlying mechanism

IPO-V2: A prospective, multicenter, randomized, comparative clinical investigation of the effects of sulodexide in preventing cardiovascular accidents in the first year after acute myocardial infarction

AbstractObjectives. This study was conducted to assess the efficacy of sulodexide, a glycosaminoglycan compound with antithrombotic properties, in preventing death and thromboembotic events after acute myocardial infarction.Background. Antithrombotic therapy has been found to play an important role in the prevention of cardiovascular events and death after acute myocardial infarction. Glycosaminoglycan-containing compounds, including sulodexide, show profibrinolytic and antithrombotic properties that render them suitable for use in patients after infarction.Methods. A total of 3,986 patients who had recovered from acute myocardial infarction were randomized to receive either the standard therapy routinely administered at each study center, excluding antiplatelet and anticoagulant drugs (control group, 1,970 patients), or the standard therapy plus sulodexide (treated group, 2,016 patients). Between 7 and 10 days after the episode of acute myocardial infarction, sulodexide was administered as a single daily 600-lipoprotein-lipase-releasing unit (LRU) intramuscular injection for the 1st month, followed by oral capsules of 500 LRU twice daily. Patients were evaluated for ≥12 months.Results. At the end of the study, 140 (7.1%) were recorded in the control group and 97 (4.8%) in the sulodexide group (32% risk reduction, p = 0.0022, chi-square test). A total of 90 patients (4.6%) in the control group had a further infarction, compared with 66 (33%) in the sulodexide group (28% risk reduction, p = 0.035). Furthermore, a reduction in left ventricular thrombus formation (evaluated by echocardiography) was observed in the sulodeside group (n = 12; 0.6%), compared with values in the control group (n = 25; 1.3%) (53% risk reduction, p = 0.027). Sulodexide was well tolerated and devoid of significant adverse events. All significant results were confirmed by “actual treatment” analyses.Conclusions. The study provides evidence that long-term therapy with sulodexide started early after an episode of acute myocardial infarction is associated with reductions in total mortality, rate of reinfarction and mural thrombus formation

Use of bivalirudin for heparin-induced thrombocytopaenia after thrombolysis in massive pulmonary embolism: a case report

A 68-year-old man was referred to the emergency department 6 h after onset of sudden acute dyspnoea. Immediate ECG showed sinus tachycardia with the typical S1-Q3-T3 pattern and incomplete right bundle branch block. The echocardiogram showed the presence of mobile thrombus in the right atrium, a distended right ventricle with free wall hypokinesia and displacement of the interventricular septum towards the left ventricle. Lung spiral computed tomography (CT) showed bilateral pulmonary involvement and confirmed the picture of a thrombotic system in the right atrium and caval vein. Thrombolytic treatment with recombinant tissue plasminogen activator (rt-PA) and heparin (alteplase 10 mg bolus, then 90 mg over 2 h) was administered. Six hours after thrombolysis bleeding gums and significant reduction in platelet count (around 50,000) were observed. Heparin was discontinued and bivalirudin (0.1 mg/kg bolus and 1.75 mg/kg per h infusion) plus warfarin was initiated and continued for 5 days until the international normalised ratio (INR) was within the therapeutic range (2.0–3.0) for 2 consecutive days, with concomitant platelet count normalisation. Lung spiral and lower abdominal CT before discharge did not show the presence of clots in the pulmonary arteries of the right and left lung. This case suggests that bivalirudin could offer promise for use in patients with heparin-induced thrombocytopaenia (HIT) after thrombolysis for massive pulmonary embolism

Evaluation of the chronic antianginal effect of molsidomine

The activity of molsidomine, a new antianginal drug, was investigated in 33 patients treated for 3 months with doses of 2 mg, three or four times daily. Exertional angina was present before treatment in 16 patients, spontaneous angina in 5, and mixed angina in twelve. Thirty patients completed the study, and three retired because of side effects. A reduction in the number of attacks of more than 75% in comparison to the pretreatment period was obtained in 20 cases, a diminution between 50% and 75% in 6, and a reduction below 50% in 6. Satisfactory increases in the duration (from 6 minutes 25 seconds to 11 minutes 40 seconds) and maximum load (89.6 to 139.3 W) were obtained in 80% of the cases of effort angina. A dramatic and statistically significant reduction of attacks was observed in the first 48 hours in 8 of 11 patients with spontaneous angina. Side effects were predominantly gastrointestinal and caused the interruption of treatment in 10% of the cases. Molsidomine seems to be a very promising drug for the treatment of effort and spontaneous angin

Effects of quinidine and diphenylhydantoin on membrane resistance in smooth muscle.

The effects of quinidine and diphenylhydantoin on the membrane electrical resistance of guinea-pig taenia coli have been studied by means of the double sucrose gap tachnique. At concentrations ranging from 2 to 7.10-minus 5 quinidine induces an evident dose-related increase of membrane resistance, as indicated by the increase of the electrotonic potential. These effects are unaffected by tetrodotoxin (10(-6)) and in the presence of various changes of ionic environment (replacement of Na by Li, increase of K or Ca or Mg concentrations). Only a concomitant rise of both K and Ca (or Mg) can prevent the effects of quinidine on membrane resistance. The rate of repetitive discharge under sustained electrical depolarization is not affected by quinidine, at concentrations increasing membrane resistance. The experiments with diphenylhydantoin showed that this drug is practically ineffective on membrane resistance, but induces a decrease of the rate of repetitive discharge under sustained depolarization