Ivan Dimich

Symptomatic atrial septal defect in infants

Abstract Clinical and hemodynamic data obtained in seven infants with atrial septal defects who developed congestive heart failure and recurrent pneumonia during the first year of life were analyzed. Auscultatory findings were variable and were not specific for atrial septal defect. Vigorous medical management was sufficient to maintain these infants during the critical first year of life. Because of the good prognosis it is imperative to differentiate this defect from other cardiac lesions which cause large left-to-right shunts and which require early surgical intervention.

Congenital heart disease in an infant with the Smith-Lemli-Opitz syndrome

The thirteenth case of the Smith-Lemli-Opitz syndrome is presented. This is the first description of congenital heart disease associated with the multiple anomalies previously described in this syndrome.

Calcified left ventricular aneurysm in children.

Abstract The case of a 7 year old boy with a calcified aneurysm of the left ventricle is reported. The diagnosis was suspected on the basis of chest roentgenogram and electrocardiogram, and verified by left heart angiocardiogram. The cause is discussed, and the literature on cardiac aneurysm in children is reviewed.

Comparative hemodynamic effects of labetalol and hydralazine in the treatment of postoperative hypertension

The antihypertensive efficacy and safety of IV labetalol were evaluated and compared with the efficacy and safety of IV hydralazine in the treatment of postoperative hypertension. Twenty patients undergoing major noncardiac surgery were entered into the study. Patients were randomized and treated for postoperative hypertension with either labetalol (n = 10) or hydralazine (n = 10). Labetalol and hydralazine both produced significant reductions in arterial blood pressure (p less than 0.001) within 10 minutes, which lasted at least 2 hours. In addition, labetalol produced a significant reduction in the heart rate and rate-pressure product without creating any adverse effects. In contrast, hydralazine produced significant sinus tachycardia requiring IV propranolol in three patients, two of whom developed transient ST segment depression. These results indicate that labetalol is safe and effective for the control of postoperative hypertension, especially in those patients who are least able to tolerate tachycardia.

Systolic Time Intervals in Infants with Congestive Heart Failure

Using the apexcardiogram as a time reference for opening and closure of the aortic valve, systolic time intervals (STI) in infants were determined in 150 normal infants ranging in age from 1 day to 1 year. Thirty infants with congestive heart failure secondary to a variety of congenital and acquired heart diseases were studied in a similar manner for comparison. The data revealed that heart failure in the infant is not marked by any one pattern of STI. In specific disease entities associated with congestive heart failure, the STI appear to be consistent. In infants with congestive heart failure due to congenital heart disease, the STI do not correspond with values reported in the adult with hypertensive or arteriosclerotic disease. The differences are explained by viewing STI in infants primarily a function of hemodynamic alterations dictated by an underlying cardiovascular anomaly rather than a result of a primary myocardial derangement. The findings in the infant with chronic heart failure due to primary myocardial disease tend to parallel data previously reported in the adult with arteriosclerotic disease and chronic heart failure.

Left Ventricle to Aorta Valved Conduit for Relief of Diffuse Left Ventricular Outflow Tract Obstruction

Operative relief of congenital tunnel subaortic stenosis by means of local incision or excision, or both, has generally been unsatisfactory. The use of a valve-bearing conduit between the left ventricular apex and thoracic aorta offers a predictable means of bypassing the left ventricular outflow obstruction. The procedure was used in a 17 year old girl with an excellent hemodynamic result. The history of operative management with diverting plantation of valved conduits in this position have not been defined, but use of these prostheses appears advisable in severe subvalvular, valvular and supravalvular obstructions that are not readily amenable to predictable and safe surgical palliation. The operation may prove useful in selected cases of idiopathic hypertrophic obstructive cardiomyopathy.

The effects of intravenous cimetidine and metoclopran ide on gastric pH and volume in outpatients

STUDY OBJECTIVE To evaluate and compare the preinduction effects of intravenously (IV) administered cimetidine alone and combined with metoclopramide on gastric contents and postoperative nausea and vomiting in outpatients undergoing elective surgery. DESIGN Patients were allocated randomly to 4 groups with 20 patients in each group. SETTING Ambulatory surgery at a university-affiliated city hospital. PATIENTS Eighty patients undergoing elective gynecologic or orthopedic procedures were studied. INTERVENTIONS Outpatients in Group 1 and inpatients in Group 2 served as controls. Outpatients in Group 3 received 300 mg of cimetidine, and outpatients in Group 4 received 300 mg of cimetidine and 10 mg of metoclopramide. All drugs were administered IV as an infusion over a 15-minute period, 30 to 45 minutes prior to induction of anesthesia. MEASUREMENTS AND MAIN RESULTS After induction of general anesthesia and endotracheal intubation, stomach contents were retrieved and volume and pH measured. Group 1 outpatients had a large residual gastric volume of 29.2 +/- 15.9 ml, with a very low pH of 2.32 +/- 1.23 and 15% frequency of postoperative vomiting. These patients are at high risk of developing significant pneumonitis in the event of the aspiration of gastric contents. The combination of cimetidine and metoclopramide in Group 4 provided the optimal, or safest, condition--i.e., high gastric pH [6.15 +/- 0.71 (p less than 0.005)] and low gastric volume [11.6 +/- 7.37 ml (p less than 0.001)], with no postoperative vomiting. CONCLUSIONS The combination of cimetidine and metoclopramide given to ambulatory patients during the preinductive phase may prevent severe pulmonary consequences should aspiration occur and is more effective in this regard than cimetidine alone.

The effect of ketorolac on recovery after outpatient gynecologic laparoscopy

Abstract Opioids, although effective postoperative analgesics, are associated with undesirable side effects. To determine whether nonopioid medication would reduce the amount required for postoperative analgesia, the efficacy of ketorolac, an injectable nonsteroidal anti-inflammatory drug, was studied in ambulatory patients undergoing gynecologic laparoscopy. Patients were randomized to a treatment group (n = 49) or control group (n = 50), then studied using a prospective double-masked design. Intraoperatively, the ketorolac treatment group received a 60-mg intramuscular injection of ketorolac; the control group received an injection of placebo (0.9% sodium chloride). Anesthetic management, postoperative pain, and the management of nausea were standardized in the two groups. Postoperative pain was treated with incremental doses of fentanyl 25 μg intravenously. Nausea and vomiting were treated with droperidol or prochlorperazine. Pain and nausea assessments were done every 30 minutes in the post-anesthesia care unit (PACU), at discharge, and at 24 hours after discharge. Postoperatively, for the first hour in the PACU, visual analog scale pain scores, as well as verbal pain scores, were statistically significantly lower in the ketorolac treatment group. Similarly, the severity of pain was twofold less in the ketorolac treatment group than in the control group. Less fentanyl was required in the ketorolac group (26 ± 20 μg, mean ± SD) compared with the control group (56 ± 32 μg, mean ± SD). However, there were no significant differences between the two groups with respect to postoperative sedation or nausea, although the incidence of vomiting requiring treatment was higher in the control group. There was high overall satisfaction of patients in both groups. In conclusion, intraoperative administration of ketorolac resulted in fewer patients awakening in pain and in a decreased need for opioid analgesic in the postoperative period. Ketorolac is an effective alternative to opioids for the control of postoperative pain in patients undergoing gynecologic laparoscopy.

Arrhythmogenic potential of dopexamine hydrochloride during halothane anaesthesia in dogs

Dopexamine hydrochloride (Dopacard®) is the novel synthetic catecholamine designed for use in the acute management of a low cardiac output status. In addition to dopaminergic receptor stimulation, dopexamine hydrochloride is a potent β2 adrenoreceptor agonist with negligible direct β1 and no alpha adrenergic effect. The objective of this study was to compare the arrhythmogenic effects of dopexamine hydrochloride and dopamine in dogs anaesthetized with halothane (1.2 MAC). The starting dose for dopexamine hydrochloride was 3.5 μg · kg−1 min−1 and for dopamine was 5 μg · kg−1 min−1. Concentrations of the drugs were increased until four or more premature ventricular contractions within 15 seconds were produced. All dogs developed ventricular tachycardia when dopamine was administered in concentrations ranging between 18–20 μg · kg−1 · min−1. Unlike dopamine, dopexamine hydrochloride even at concentrations as high as 50 μg · kg−1· min−1 did not induce any atrial or ventricular ectopic beats. Lack of β-1 and alpha adrenergic agonist effects is a likely explanation for low arrhythmogenicity of dopexamine hydrochloride. Both drugs increase cardiac output; dopexamine hydrochloride primarily by a dose-related increase in heart rate and increased aflerload. At the maximal concentration dopexamine hydrochloride increased heart rate from 114 to 150 beat · min−1, mean arterial pressure decreased from 81 mmHg to 45 mmHg and SVR decreased from 2418 to 962 dyne · sec−1cm−5. Myocardial contractility increased only moderately, as evaluated by dP/dt, which increased from 1290 to 1696 mmHg · sec−1. Dopamine had a more marked inotropic effect: the dP/dt increased, at the maximal concentration, from 1480 to 2570 mmHg · sec−1. Dopamine also produced vasoconstriction: SVR increased from 2325 to 2683 dyne · sec · cm−5 and mean arterial pressure from 86 mmHg to 110 mmHg. In conclusion, dopexamine hydrochloride is less arrhythmogenic than dopamine, has less of an inotropic effect, and a greater effect on aflerload.RésuméL’hydrochlorure de dopexamine (Dopacard®) est une nouvelle catécholamine synthétique destinée au traitement des états de bas débit cardiaque. En plus de stimuler les récepteurs dopaminergiques, l’hydrochlorure de dopexamine est un agoniste adrénorécepteur β2 puissant avec effets directs β1 négligeables mais sans effets alpha-adrénergiques. Cette étude vise à comparer les effets arhythmogènes de l’hydrochlorure de doxepamine avec la dopamine sur des chiens anesthésiés à l’halothane (1,2 MAC). La dose initiale dhydrochlorure de dopexamine est de 3,5. μg · kg−1 · min−1 et de dopamine de 3,5 μg · kg−1 · min−1. La concentration des drogues a été augmentée jusqu’à l’apparition de quatre contractions prématurées ou plus en deçà de 15 secondes. Tous les chiens ont développé de la tachycardie ventriculaire pendant l’administration de dopamine à des doses se situant entre 18 et 20 pg · kg−1 · min−1. Contrairement à la dopamine, l’hydrochlorure de dopexamine n’a pas provoqué de battements ectopiques auriculaires ou ventriculaires même à des concentrations aussi élevées que 50 μg · kg−1 · min−1. L’absence d’effets β1 et agonistes alpha-adrénergiques constitue une explication plausible pour la faible arrythmogénécité de l’hydrochlorure de dopexamine. Les deux drogues augmentent le débit cardiaque; l’hydrochlorure de dopexamine principalement par augmentation en rapport avec la dose de la fréquence cardiaque et une baisse de la post-charge. A la concentration maximale dhydrochlorure de dopexamine, la fréquence cardiaque augmente de 114 à 150 b · min−1, la pression artérielle moyenne baisse de 81 à 45 mmHg et la résistance vasculaire systémique (RVS) baisse de 2418 à 962 dyne · sec−1 · cm−5. La contractilité myocardique mesurée par le dP/dt n’augmente que modérément de 1290 à 1696 mmHg · sec−1. Par contre, la dopamine a un effet inotrope plus marqué: le dP/dt augmente de 1480 à 2570 mmHg · sec−1 à la concentration maximale. La dopamine produit aussi de la vasoconstriction: la RVS augmente de 2325 à 2683 dyne · sec · cm−5 et la pression artérielle moyenne de 68 mmHg à 110 mmHg. En conclusion, l’hydrochlorure de dopexamine est moins arythmogène que la dopamine, a moins d’effets inotropes mais agit plus sur la post-charge.

Reversal of the adverse cardiovascular effects of intravenous diltiazem in anesthetized dogs

Intravenous diltiazem can be used to treat myocardial ischemia, hypertension, and supraventricular dysrhythmias, but significant adverse effects including atrioventricular block and hypotension have been reported. At the present time, there is controversy as to which drug is most effective in reversing these sequelae. This study was designed to assess the effectiveness of calcium chloride v epinephrine in reversing these side effects. The hemodynamic and electrophysiologic effects of diltiazem infusion were investigated in eight dogs anesthetized with fentanyl and nitrous oxide/oxygen. This study confirmed that diltiazem infusions in high concentrations produced predominantly atrioventricular conduction depression followed by profound hypotension. Epinephrine infusion proved to be most effective in attenuating and eliminating each of these deleterious side effects. In contrast, calcium chloride did not significantly increase heart rate or blood pressure or reverse atrioventricular block. In two instances calcium chloride produced further depression of atrioventricular conduction, leading to severe bradycardia and sinus arrest. Although calcium chloride increased left ventricular contractile force (LV dP/ dt) and cardiac index (CI), mean arterial pressure was not affected and SVR was further decreased. This study indicates that calcium chloride should not be given to reverse the side effects of diltiazem in the presence of atrioventricular conduction block or profound hypotension. Calcium chloride is indicated only when isolated myocardial depression is present and after the calcium channels have been reopened by epinephrine.