The congenital type of atrial flutter has a poor prognosis when unresponsive to digoxin (Moller, Davachi, and Anderson, 1969). Recorded experience with cardioversion is limited but it has been suggested that this type of flutter is refractory to electric countershock (Rodriguez-Coronel, Sueblingvong, and Hastreiter, 1968).We report an infant with congenital heart defects and congenital atrial flutter who appeared resistant to digoxin and ,B-blockade (practolol) but readily reverted to sinus rhythm with direct current (DC) cardioversion.Case Report This was the second pregnancy of a 25-year-old whose health was good until mild hypertension developed at term. Labour was induced at 40 weeks, and the fetal heart was noted to be rapid and irregular. A mature female infant weighing 3 * 8 kg was delivered by emergency caesarean section. No meconium staining was evident, and the Apgar score at one minute was 9. The infant remained active, sucked well, and was pink breathing air.The apex beat was consistently 180-200/minute. No cardiac murmurs were heard at this time and there were no signs of respiratory distress. X-ray showed slight cardiomegaly and clear lung fields. ECG showed atrial flutter with varying AV block and a ventricular rate around 180/minute.An attempt was made to control the ventricular rate using digoxin orally. A total dose of 0 3 mg over the first 24 hours was given, and 0 075 mg daily thereafter. After 3 days there was no change in the underlying arrhytnmia or the ventricular rate (Fig.). At this time a soft systolic murmur became audible at the left sternal edge.At the age of 4 days cardiac catheterization revealed an atrial septal defect with a pulmonary-systemic flow ratio of 2: 1 and a minor degree ofaortic coarctation. During the procedure the atrial flutter reverted to sinus rhythm for two short periods.At 5 days digoxin was stopped. After 24 hours, and with continuous ECG monitoring, practolol was given twice within one hour by slow i.v. injection in a dose of 05 mg diluted in 10 ml saline. No effect was noted on the heart rate or rhythm. Oral practolol 2-2 mg/kg twice daily was given and increased to four times daily without effect on rate or rhythm (Fig.).By 10 days the baby's condition was deteriorating with tachypnoea and feeding difficulty. The liver was palpable two fingers' breadth below the costal margin. X-ray revealed increasing cardiomegaly. DC cardioversion was, therefore, attempted.No anaesthetic was given. Adult electrodes (9 cm diameter) were placed on the right midsternal border and on the apex with about nine-tenths of the surface area of the paddles masked by insulating tape. A shock of 10 watt-seconds was given from a Lown cardiorater.
SUMMARY Electrophysiological studies showed ventricular tachycardia in five patients (four male, one female) with isolated right ventricular dilatation. All had been asymptomatic before the onset of palpitation which had developed in adolescence or early adult life. Tachycardia had been associated with syncope in four patients, and three had been resuscitated from ventricular fibrillation before investigation. The electrocardiogram during ventricular tachycardia showed a left bundle branch block pattem, and endocardial mapping at electrophysiological study confirmed the right ventricular origin. The presenting tachycardia could be induced in all patients by programmed stimulation, and in three patients ventricular tachycardia of differing configuration could be induced, but the right ventricular origin and left bundle branch block pattern were maintained. In two patients ventricular tachycardia degenerated into ventricular fibrillation. Cineangiography, cross sectional echocardiography, and multigated radionuclide angiography confirmed the dilated abnormal right ventricle while indicating that left ventricular function was normal. On resting electrocardiograms T wave inversion over the right precordial leads was the sole abnormality. There were no signs of right heart failure and exercise tolerance was normal. Four patients have received maintenance treatment with antiarrhythmic drugs, and one had undergone operative mapping and ablative surgery.Thus ventricular tachycardia complicating right ventricular dilatation may be associated with serious symptoms and ventricular electrical instability; and in adults it may be suspected on clinical grounds by inverted T waves in the right precordial leads.
SUMMARY Twenty four hour recordings of heart rate and respiration were made on 60 infants with lower respiratory tract infection (LRTI) during the acute phase of the illness, on 20 infants with upper respiratory tract infection (URTI), and on 21 control infants. Infants with LRTI and URTI had more apnoeic episodes of longer than 10 seconds compared with controls. The length of apnoeic episodes was greatest in the LRTI group but their frequency decreased with age. In both the LRTI and URTI groups apnoea was associated with bradycardia but the LRTI group also suffered an appreciable number of episodes of bradycardia without apnoea.Lower respiratory tract infection (LRTI) is a common cause of hospital admission in children aged under 1 year. Apnoea has been noted in infants with severe respiratory tract infections' and also, in a retrospective survey, in those less severely affected.2 Apnoea in babies with LRTI may also be relevant in the sudden infant death syndrome. Upper and lower respiratory tract infection, not generally sufficiently severe to explain death, have been found at necropsy in infants found dead at home,3 4 and it has been suggested that minor respiratory illness may trigger sudden apnoea.5 6 We studied 3 groups of children; 1 group with LRTI, 1 group with upper respiratory tract infection (URTI), and 1 control group without respiratory disease to determine the incidence of apnoea. We aimed to establish whether apnoea occurred more frequently during severe illness, whether it was associated with bradycardia, and whether bradycardia occurred alone. Patients and methods Electrocardiographic tracings (ECG) and respiration were recorded over 24 hours on 101 infants. The LRTI group comprised 60 infants aged (mean ± SD) 16-3 ± 10.4 weeks and birthweight (mean ± SD) 2.9 + 0.7 kg. We did not distinguish between bronchitis, bronchiolitis, or bronchopneumonia.7 The URTI group comprised 20 infants aged (mean ± SD) 12.1 ± 6.2 weeks and birthweight (mean ± SD) 3.2 ± 0.5 kg. The 21 control infants studied were aged (mean ± SD) 12-1 ± 6.2 weeks and birthweight (mean ± SD) 2.9 ± 0 5 kg. In all cases a full history was obtained from parents and chest x-ray films were taken. In all the LRTI and URTI patients nasopharyngeal secretions were collected for bacterial culture and in 60% of these infants secretions were taken for viral studies.Impedance pneumography was used to monitor respiration. Changes in transthoracic electrical impedance produced a reliable record of respiration.8 9 In all infants respiration signals were obtained from 2 electrodes placed on opposite sides ofthe chest wall, and ECG from the same 2 electrodes and a reference electrode. The monitor system was a Healthdyne infant monitor fitted with a Medilog cassette recorder (Oxford Medical Systems). Two channels of the recording system were used for the respiration and ECG signal and a third channel for timing. The recordings on the patients with URTI and LRTI were taken when the illness was severe and the tapes were stored for analysis.
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