Presence Of Cardiac Dysfunction Research Articles

Is it time to add aortic isthmus evaluation to the repertoire of Doppler investigations for placental insufficiency?

Is it time to add aortic isthmus evaluation to the repertoire of Doppler investigations for placental insufficiency?

Elevated plasma levels of N-terminal pro-brain natriuretic peptide in patients with chronic hepatitis C during interferon-based antiviral therapy

To investigate plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), an established marker of cardiac function, in patients with chronic hepatitis C during interferon-based antiviral therapy. Using a sandwich immunoassay, plasma levels of NT-proBNP were determined in 48 patients with chronic hepatitis C at baseline, wk 24 and 48 during antiviral therapy and at wk 72 during follow-up. Plasma NT-proBNP concentrations were significantly increased (P<0.05) at wk 24, 48 and 72 compared to the baseline values. NT-proBNP concentrations at baseline and wk 24 were closely correlated (r = 0.8; P<0.001). At wk 24, 7 (14.6%) patients had NT-proBNP concentrations above 200 ng/L compared to 1 (2%) patient at baseline (P = 0.059). Six of these 7 patients had been treated with high-dose IFN-alpha induction therapy. In multiple regression analysis, NT-proBNP was not related to other clinical parameters, biochemical parameters of liver disease or virus load and response to therapy. Elevated levels of NT-proBNP during and after interferon-based antiviral therapy of chronic hepatitis C may indicate the presence of cardiac dysfunction, which may contribute to the clinical symptoms observed in patients during therapy. Plasma levels of NT-proBNP may be used as a diagnostic tool and for guiding therapy in patients during interferon-based antiviral therapy.

Coupled pacing improves cardiac efficiency during acute atrial fibrillation with or without cardiac dysfunction.

Coupled pacing (CP), a method for controlling ventricular rate during atrial fibrillation (AF), consists of a single electrical stimulation applied to the ventricles after each spontaneous activation. CP results in a mechanical contraction rate approximately one-half the rate during AF. Paired stimulation in which two electrical stimuli are delivered to the ventricles has also been proposed as a therapy for heart failure. Although paired stimulation enhances contractility, it greatly increases energy consumption. The primary hypothesis of the present study is that CP improves cardiac function during acute AF without a similar increase in energy consumption because of the reduced rate of ventricular contractions. In a canine model, CP was applied during four stages: sinus rhythm (SR), acute AF, cardiac dysfunction (CD), and AF in the presence of cardiac dysfunction. The rate of ventricular contraction decreased in all four stages as the result of CP. In addition, we determined the changes in external cardiac work, myocardial oxygen consumption, and myocardial efficiency in the each of four stages. CP partially reversed the effects of AF and CD on external cardiac work, whereas myocardial oxygen consumption increased only moderately. In all stages but SR, CP increased myocardial efficiency because of the marked increases in cardiac work compared with the moderate increases in total energy consumed. Thus this pacing therapy may be a viable therapy for patients with concurrent atrial fibrillation and heart failure.

Assessment of factors that influence weaning from long-term mechanical ventilation after cardiac surgery.

To analyze parameters of respiratory system mechanics and oxygenation and cardiovascular alterations involved in weaning tracheostomized patients from long-term mechanical ventilation after cardiac surgery. We studied 45 patients in their postoperative period of cardiac surgery, who required long-term mechanical ventilation for more than 10 days and had to undergo tracheostomy due to unsuccessful weaning from mechanical ventilation. The parameters of respiratory system mechanics, oxygenation and the following factors were analyzed: type of surgical procedure, presence of cardiac dysfunction, time of extracorporeal circulation, and presence of neurologic lesions. Of the 45 patients studied, successful weaning from mechanical ventilation was achieved in 22 patients, while the procedure was unsuccessful in 23 patients. No statistically significant difference was observed between the groups in regard to static pulmonary compliance (p = 0.23), airway resistance (p = 0.21), and the dead space/tidal volume ratio (p = 0.54). No difference was also observed in regard to the variables PaO2/FiO2 ratio (p = 0.86), rapid and superficial respiration index (p = 0.48), and carbon dioxide arterial pressure (p = 0.86). Cardiac dysfunction and time of extracorporeal circulation showed a significant difference. Data on respiratory system mechanics and oxygenation were not parameters for assessing the success or failure. Cardiac dysfunction and time of cardiopulmonary bypass, however, significantly interfered with the success in weaning patients from mechanical ventilation.

Clinically Recognized Cardiac Dysfunction: An Independent Determinant of Mortality Among Critically III Patients: Is There a Role for Serial Measurement of Cardiac Troponin I?

To determine the relative importance of clinically recognized cardiac dysfunction and unrecognized cardiac injury to hospital mortality. Prospective, blinded, single-center study. Medical ICU of Barnes-Jewish Hospital, St. Louis, a university-affiliated teaching hospital. Two hundred sixty adult patients requiring admission to the medical ICU. Daily blood collection. The presence of cardiac dysfunction (myocardial infarction, unstable angina, cardiac arrest, or congestive heart failure) as determined by the physicians responsible for the care of the patient. Daily measurement of levels of cardiac troponin I, a sensitive, highly specific, and long-lived marker of myocardial injury. Fifty-five (21.2%) patients had clinical evidence of cardiac dysfunction, among whom 22 (40%) had an elevated level of cardiac troponin I. A total of 41 (15.8%) patients had evidence of acute myocardial injury based on elevated levels of cardiac troponin I. Patients with clinically recognized cardiac dysfunction had a significantly greater hospital mortality rate compared to patients without clinically recognized cardiac dysfunction (45.5% vs 10.2%; p < 0.001). Similarly, patients with elevated blood levels of cardiac troponin I had a greater hospital mortality rate compared to patients without elevated blood levels of cardiac troponin I (26.8% vs 16.0%; p = 0.095). Multiple logistic-regression analysis controlling for potential confounding variables demonstrated that the presence of clinically recognized cardiac dysfunction was independently associated with hospital mortality (adjusted odds ratio = 3.0; 95% confidence interval = 1.9 to 4.8; p = 0.016). However, having an elevated blood level of cardiac troponin I was not found to be an independent determinant of hospital mortality. Among critically ill medical patients, clinically recognized cardiac dysfunction is an independent determinant of hospital mortality. The identification of unrecognized cardiac injury, using serial measurements of cardiac troponin I, did not independently contribute to the prediction of hospital mortality.

肺動脈内寄生の犬糸状虫による心機能の変化

The present study was made to investigate the effects of the initial stage of filariais on canine cardiac function. Controls (n=10, BW 7.9±0.4kg, mean±SEM) and dogs with heartworm (n=9, BW 8.8±0.3 kg) were used. Electrocardiographic examination detected that the amplitude (3.8±0.3 mV) and duration (3.9±0.2 msec) of the P wave were increased in dogs with heartworm. Catheteric examination of the heart revealed the cardiac index (5.1±0.21/min/m2) to be significantly decreased (p<0.005), and right and left ventricular end diastolic pressures (7.3±0.7 and 12.6±2.1 mmHg) were greatly increased (P<0.025), compared with the controls. These results might indicate the presence of cardiac dysfunction in the initial stage of filariasis. The detail mechanism in the development of cardiac dysfunction is still unknown.