Biomedical subjects
Publications and source records attributed to D Alehan.
Cardiac hydatid cyst is extremely rare in children. We report a case of a cardiac echinococcal cyst in an 11 year old boy, diagnosed by two-dimensional echocardiography and magnetic resonance imaging (MRI). The cyst was located in the posterior wall of the left ventricle and was excised surgically. Echocardiographic and MRI findings are discussed.
We prospectively evaluated 80 patients with syncope, between January 1991 and January 1992 to determine the causes of syncope in children. There were 35 male and 45 female patients, whose mean age was 10.5 years. A single syncopal attack had occurred in 30 patients and multiple attacks in 50. A cardiovascular cause was established in 22 (27.5%) patients and a noncardiovascular cause in 36 (45%). The cause remained unknown in 22 patients (27.5%). Vasovagal syncope was the leading cause of syncope in these patients with an incidence of 32.5%. These findings suggest that every patient who has even one syncopal attack should be promptly investigated since the underlying cause could be a life-threatening one.
Valvar heart disease is a rare complication of juvenile rheumatoid arthritis (JRA), the aortic valve being most commonly affected. Reported cases with symptomatic mitral involvement are rare. We describe a 13-year-old boy with seronegative, polyarticular onset of JRA in whom mitral and aortic valve insufficiency was diagnosed by clinical and laboratory investigations. Two-dimensional and continuous-wave Doppler echocardiography confirmed mild pericardial effusion with moderate mitral and mild aortic insufficiency. Cardiac assessment and echocardiographic follow-up are recommended in all patients with JRA.
Unexplained syncope may cause diagnostic and therapeutic problems in children. The head-up tilt test has been shown to be a useful tool for investigating unexplained syncope, especially for diagnosis of neurally mediated syncope. In this study 20 patients aged 9-18 years (12.0 +/- 2.5 years) with syncope of unknown origin and 10 healthy age-matched children were evaluated by head-up tilt to 60 degrees for 25 minutes. The test was considered positive if syncope or presyncope developed in association with hypotension, bradycardia, or both. If tilting alone did not induce symptoms (syncope or presyncope), isoproterenol infusion was administered with increasing doses (0.02-0.08 mu g/kg per minute). During the tilt test, symptoms were elicited in 15 (75%) of the patients with unexplained syncope but in only one (10%) of the control group (p < 0.001). The sensitivity of the test was 75% and its specificity 90%. Three patterns of response to upright tilt were observed in symptomatic patients: vasodepressor pattern with an abrupt fall in blood pressure in 67%; cardioinhibitory pattern with profound bradycardia in 6%; and mixed pattern in 27%. In patients with positive head-up tilt, there were sudden decreases in systolic blood pressure (from 130 +/- 15 to 61 +/- 33 mmHg) and in mean heart rate (from 147 +/- 26 to 90+/-38 beats per minute) (p < 0.001) during symptoms. Treatments with atenolol 25 mg/day has shown complete suppression of syncope in positive responders during a mean follow-up period of 18 +/- 6 months. The head-up tilt test is a noninvasive, sensitive, specific diagnostic tool for evaluating children with unexplained syncope.
Torsade de pointes is a polymorphic ventricular tachycardia. Causes of torsade de pointes are well described. Although intracranial disease can produce dramatic electrocardiographic (ECG) changes, we are not aware of previous cases with torsade de pointes and encephalitis. We report a case with encephalitis who developed torsade de pointes, and was treated with temporary ventricular pacing and magnesium infusion.
Right ventricular outflow tachycardia is a distinct subgroup of idiopathic ventricular tachycardia (VT) with characteristic clinical and electrophysiologic properties. This study was planned to evaluate the effects of adenosine on idiopathic right ventricular tachycardia in children, and to assess the long-term efficacy of verapamil treatment. Diagnostic tests including electrocardiogram, chest roentgenogram, echocardiogram, exercise stress test and 24-hour ambulatory electrocardiographic monitoring were performed in each patient. Adenosine was administered in increasing amounts until an effective dose or a maximal dose of 300 micrograms/kg was reached. In adenosine-sensitive patients verapamil was given orally (3-10 mg/kg/day) for long-term suppression of arrhythmia. Seven patients with a mean age of 10.2 +/- 4.7 years were enrolled in the study. There were five male and two female patients. Six patients had VT, and one patient had frequent ventricular ectopic bests. Arrhythmia originated from the right ventricle in all patients. Adenosine was effective in terminating the arrhythmia in all patients, with a mean effective dose of 183 +/- 75 micrograms/kg. Favorable long-term results (mean follow-up period 17 +/- 8 months) were obtained with verapamil treatment at an average dose of 6.3 +/- 2.2 mg/kg. In conclusion, adenosine can be used effectively for termination of VT originating from the right ventricular outflow tract in children. In these patients verapamil may be considered as the drug of choice for long-term therapy.
Two cases are described in which severe mechanical hemolytic anemia developed after surgical repair of primum atrial septal defect (ASD) and cleft mitral valve. In both cases there was residual mitral regurgitation after repair. Moderate mitral regurgitation and collision of the regurgitant jet with the teflon patch used for repair of the primum ASD were detected by color-Doppler echocardiography imaging. Laboratory tests showed normochromic normocytic anemia, increased indirect serum bilirubin, decreased plasma haptoglobin and hemoglobinuria. The peripheral blood smear contained numerous fragmented red cells. Following another surgical correction of the mitral valve (repair or mitral valve replacement), there was no more hemolysis. The two presented cases show that foreign materials in association with localized intracardiac turbulence may cause severe hemolysis.
Blade atrial septostomy was performed in 18 patients, including 14 with transposition of the great arteries, three with tricuspid atresia and one with severe mitral stenosis and ventricular septal defect. The patients' ages ranged from 25 to 210 days (mean: 108 +/- 64 days), and weights ranged from 3.0 to 6.0 kg. Following blade septostomy, partial arterial pressure of oxygen (PaO2) increased from an average of 22 +/- 3.3 mmHg to 38.9 +/- 7.6 mmHg (p < 0.001), and prompt clinical improvement was observed in the majority of patients. Significantly decreased atrial pressures (from 8.16 +/- 6.1 to 3.93 +/- 2.2 mmHg, p < 0.01) and significantly enlarged inter-atrial openings (from 1.6 +/- 0.9 to 7.5 +/- 1.8 mm, p < 0.001) were achieved with successful blade atrial septostomy. Blade atrial septostomy is an effective and life-saving procedure in patients who require nonrestrictive inter-atrial communication.
The antiarrhythmic effect of amiodarone was examined in this retrospective study in a group of 20 patients with a mean age of 8.5 +/- 6.7 years (range 42 days to 20 years, median 9 years). Five patients with atrial flutter, one patient with atrial fibrillation, two patients with an intermediate rhythm between atrial flutter and atrial fibrillation, four patients with chaotic atrial tachycardia, three patients with atrioventricular reentry tachycardia, two patients with junctional ectopic tachycardia, and three patients with ventricular arrhythmias were treated with amiodarone. The mean duration of therapy was 9.1 +/- 12.3 months (range 1 month to 4 years). Before amiodarone treatment, 18 patients had been unresponsive to various antiarrhythmic drugs (range 1-8, median 2). Two patients received amiodarone as an initial therapy. It was administered orally at a dose of 10 mg/kg once per day for 10 days and then decreased to 5 mg/kg once per day. Amiodarone was effective in 16 patients (80%). Side effects occurred in three patients, including thyroid dysfunction, elevation of liver enzymes, and keratopathy. All side effects disappeared upon cessation of the therapy. We recommend amiodarone for the treatment of childhood arrhythmias, especially for the refractory types.
Syncope is defined as a sudden transient loss of consciousness. Vasovagally mediated hypotension and bradycardia are believed common, yet difficult to diagnose, causes of syncope in healthy children and adolescents. These episodes are often both sudden and sporadic in nature and, if recurrent and severe (malignant vasovagal syncope), can be a source of morbidity and possibly mortality. Head-up tilt testing has emerged as a useful investigation in patients who are thought to have recurrent vasovagal syncope with systemic hypotension, bradycardia, or both, and it has been suggested as a potential method to test for vasovagal episodes. Sertraline hydrochloride, a serotonin reuptake inhibitor, has been reported to be effective in preventing the vasovagal syncopal episodes in children and adults. Here, two cases of recurrent, unexplained syncope are presented. Both were under sertraline therapy and underwent provocative head-up tilt testing that resulted in asystole.
A seven-year-old boy with interrupted left pulmonary artery, arteriovenous fistulas and atrial septal defect is presented. The anomalies were identified by echocardiography and angiography. On pulmonary artery angiograms, left pulmonary artery discontinuity (as though the distal segment had been interrupted), diffuse granulary opacification of right lung fields, and early visibility of the left atrium were observed.
The Fontan operation is used to supply a ventriculo-arterial connection in patients with tricuspid atresia. An important complication is the obstruction of the conduit that may necessitate reoperation. In these patients balloon dilation of the conduit stenosis has been advocated as a method to relieve the obstruction and postpone surgical replacement. While there are several reports about the balloon dilation of stenotic valved conduits, we do not have enough information about the results of balloon dilation of nonvalved conduits. We performed successful balloon dilations in two patients with tricuspid atresia who underwent the Fontan operation and had stenotic nonvalved conduits. In the first patient, the stenosis was relieved but recurred. A second balloon dilation procedure was performed, and the patient has been symptom free for one year. In the second patient, the stenosis was relieved but recurred. Our preliminary results suggest that balloon dilation is an efficient method to relieve the obstruction in stenotic nonvalved conduits and can be repeated successfully if the stenosis recurs.
Heart rate, systolic and diastolic blood pressure and electrocardiographic changes were studied in 80 healthy children during treadmill exercise with Bruce protocol. Mean duration of exercise in boys increased from 10.01 +/- 1.61 minutes at age four to six years with a mean body surface area of 0.75 +/- 0.06 m2, to 17.86 +/- 2.66 minutes at age 13 to 15 years with a mean body surface area of 1.48 +/- 0.10 m2. Mean endurance time in girls increased from 11.06 +/- 1.92 minutes at age four to six years with a mean body surface area of 0.76 +/- 0.08 m2, to 15.69 +/- 2.23 minutes at age 13 to 15 years with a mean body surface area of 1.41 +/- 0.07 m2. Mean maximal heart rate was 193.38 +/- 10.89 beats/minute in boys and 196.78 +/- 10.99 beats/minute in girls. The maximum level of systolic blood pressure attained at peak exercise was lower in girls. Although data of healthy Turkish children including mean endurance time, heart rate and blood pressure responses to exercise were consistent with the results from several countries using the Bruce protocol, mean maximal heart rates for all groups were slightly higher than those obtained with the Balke protocol. The data obtained from this study offers age- and size-appropriate normal data in both sexes in healthy Turkish children and may be used as reference values during treadmill exercise.
We evaluated left and right ventricular diastolic functions by pulsed Doppler echocardiography in 16 children with dilated cardiomyopathy and in 20 healthy age-matched control subjects. The cardiomyopathy group demonstrated an abnormal relaxation pattern of the left ventricle. In the cardiomyopathy group compared to normal subjects, peak early filling velocities (43.3 +/- 11 cm/s versus 60.4 +/- 11 cms/s, p < 0.01), the corresponding velocity-time integrals (3.3 +/- 1.4 cm versus 4.6 +/- 1.2 cm, p < 0.01) and the ratio of peak early filling velocity to late filling velocity (1.22 +/- 0.47 versus 1.49 +/- 0.23, p < 0.05) were significantly lower whereas isovolumic relaxation time was significantly longer (58.9 +/- 19.8 ms versus 49.7 +/- 8.9 ms, p < 0.05). In addition, right ventricular diastolic filling was also impaired in children with dilated cardiomyopathy. Peak early filling velocities (41 +/- 7.9 cm/s versus 47.5 +/- 8.8 cm/s, p < 0.05) and the corresponding velocity time integrals (3.0 +/- 1.0 cm versus 3.87 +/- 1.1 cm, p < 0.05) were significantly decreased, while isovolumic relaxation time was significantly increased (60.6 +/- 16.3 ms versus 52.2 +/- 12.8 ms, p < 0.05) in the cardiomyopathy group. The study suggests that abnormalities of both right and left ventricular diastolic function may occur, and should be searched for, in pediatric patients with dilated cardiomyopathy.