Potential additional indicators for pacemaker requirement in isolated congenital atrioventricular block.

Low heart rate is the predominantly used indication for pacemaker intervention in patients with isolated congenital atrioventricular block (CAVB). The aim of this study was to compare the difference in heart rates recorded with ECG and Holter monitoring between paced (PM) and nonpaced (NPM) patients with isolated CAVB before pacemaker implantation to identify additional predictors for future PM need. Retrospective evaluation of atrial and ventricular rates (electrocardiography) and minimal and maximal (Holter) heart rates in 129 CAVB patients prior to PM implantation (n = 93) was performed, and results are expressed in V adjusted for age and sex. The average V score for the atrial rate was 0.51 (n = 50) in the PM group and 0.60 (n = 22) in the NPM group (not-significant). The average z score for the ventricular (average) rate was -0.91 (n = 83) in the PM group and -0.93 (n = 33) in the NPM group (not-significant). Minimal heart rate was -0.94 (n = 61) in the PM group and -0.86 (n = 25) in the NPM group (not significant). Maximal heart rate was -0.96 (n = 61) in the PM group and -0.95 (n = 26) in the NPM group (not significant). Initial recordings of the average heart rate and the minimal and maximal heart rate recorded during Holter monitoring do not seem to predict future pacemaker need in patients with CAVB. Studies with exercise stress tests are needed to confirm these findings.

Dilated cardiomyopathy in isolated congenital complete atrioventricular block: early and long-term risk in children.

OBJECTIVES: We sought to identify the risk factors predicting the development of dilated cardiomyopathy (DCM) in patients with isolated congenital complete atrioventricular block (CCAVB). BACKGROUND: Recently evidence has emerged that a subset of patients with CCAVB develop DCM. METHODS: This was a retrospective study of 149 patients with CCAVB who had heart size and left ventricular (LV) function assessed by echocardiography and chest radiography over a follow-up period of 10 +/- 7 years. RESULTS: Nine patients developed DCM at the age of 6.5 +/- 5 years. No definite cause could be identified. In these nine patients, CCAVB was diagnosed in eight at 23 +/- 2.3 weeks gestation and in one at birth. Maternal SSA/SSB antibodies were confirmed in seven of the nine patients. Pacemakers were implanted in eight patients in the first month and in one patient at five years of age. The initial left ventricular end-diastolic dimension (LVEDD) was in the 96th +/- 2.6 percentile and the cardiothoracic (CT) ratio was 64 +/- 3.8% in the nine patients who developed DCM, and differed significantly in patients with CCAVB (p < 0.005) who did not develop DCM. The LVEDD and CT ratio did not decrease in the patients with CCAVB and DCM, but decreased significantly in the patients with CCAVB without DCM (p < 0.001) once pacing was initiated. Two patients with DCM died within two months of diagnosis; one patient is neurologically compromised; two patients received a heart transplant; and four patients are listed for heart transplantation. CONCLUSIONS: Isolated CCAVB is associated with a long-term risk for the development of DCM. Risk factors may be SSA/SSB antibodies, increased heart size at initial evaluation and the absence of pacemaker-associated improvement.

Abnormalities in liver function and coagulation profile following the Fontan procedure.

OBJECTIVE: To investigate liver function and coagulation disorders in patients with a Fontan circulation at different time intervals after surgery. DESIGN: Retrospective analysis of clinical data and cross sectional study relating liver function and coagulation profile to time since surgery, in 28 surviving patients after the modified Fontan procedure. PATIENTS: 20 patients (71%) with atriopulmonary anastomosis, seven (25%) with atrioventricular anastomosis, and one (4%) with total cavopulmonary connection. Follow up ranged from 2.0 to 21.8 years (mean 11.1). RESULTS: Abnormal liver function tests, mainly reflecting cholestasis, were present in 21 patients who had a significantly longer follow up (p < 0.01). Protein synthesis was normal in almost all patients. Coagulation profile showed abnormalities in 22 patients. "Procoagulant" abnormalities-that is, decreased plasminogen and protein C activity-were found in 11 and five patients, respectively. The extent of these abnormalities was less in patients with a longer follow up. Anticoagulant abnormalities were factor V deficiency in 16 patients and factor VII deficiency in 17, resulting in a prolonged prothrombin time in 19 patients. Thirteen patients had both pro- and anticoagulant abnormalities. A prethrombotic state was present in five patients, with a significantly longer mean time interval since surgery (p = 0.05). Thus, although the individual procoagulant indices decreased with increasing time intervals since surgery, a prethrombotic state was found particularly in patients with a long term follow up. CONCLUSIONS: Mild cholestasis was mainly present in Fontan patients with a long duration of follow up. Along with laboratory procoagulant abnormalities indicating a prethrombotic state, anticoagulant abnormalities were also present. The coagulation profile varied at different time intervals after surgery. Thus detailed evaluation should be performed regularly, and the use of anticoagulants should be considered in every patient. Long term prospective studies are needed to evaluate the individual fluctuations of coagulation profile over time following a Fontan procedure.

Activity of "seroquel" (ICI 204,636) in animal models for atypical properties of antipsychotics: a comparison with clozapine.

The pharmacologic treatment of schizophrenia still suffers from two major problems: (1) most antipsychotic drugs still induce severe neurologic (extrapyramidal) side effects; (2) few antipsychotic drugs are effective in treating the negative symptoms of schizophrenia. In the present study, we have evaluated the effects of ICI 204,636 in the rat paw test and the amphetamine-induced social isolation in monkeys and compared them with the effects of clozapine. The paw test has been shown to be a valid model for differentiating classic and atypical neuroleptic drugs. The monkey social isolation model seems to represent one of the few animal models with validity for the negative symptoms of schizophrenia. The results show that both ICI 204,636 and clozapine had the profile of an atypical antipsychotic in the paw test, suggesting a reduced propensity to induce extrapyramidal side effects in humans. Likewise, ICI 204,636 and clozapine were found to prevent the amphetamine-induced social isolation in monkeys, suggesting a good therapeutic effect mitigating the negative symptoms in schizophrenia. Overall, the data suggest that ICI 204,636 may represent a new and interesting antipsychotic drug, closely resembling clozapine.

Partial abnormal pulmonary venous return in Turner syndrome.

Three cases of partial anomalous pulmonary venous return, in one case combined with coarctation of the aorta and in another with discrete subaortic stenosis, are described in patients with Turner syndrome. In two of them the right and left superior pulmonary veins drained into the right superior vena cava and left innominate vein respectively. Remarkably, in all three cases the atrial septum was intact. We feel that this unique combination probably is not purely coincidental, but might rather be specific for Turner syndrome.

An asymmetric bulging of the chest as a leading sign of a cardiac fibroma in a child.

A 17-month-old child with an asymmetrical bulging of the chest due to an intramural fibroma of the heart is described. The clinical symptoms that may be caused by cardiac tumours are discussed. To detect these tumours several investigations can be performed, of which echocardiography is the most specific. Surgical resection of these tumours should be attempted, even if a complete resection is not possible.

The Fontan procedure in the absence of the interatrial septum. Failure of its principle?

The Fontan principle, defined as a procedure in which the right ventricle is bypassed in order to convey desaturated venous blood from the right atrium to the lungs, is presently applied for a wide variety of congenital heart malformations including those in which there is no suitable ventricular pumping chamber. Recently, the procedure has also been advocated for complex malformations that require atrial septation or intra-atrial rerouting. The present report evaluates our experience in four patients with such complex malformations. Three had a complete form of atrioventricular septal defect with double-outlet right ventricle and one patient had left atrioventricular valve atresia. The common atrium was morphologically right in two patients and morphologically left in one. In each of these instances anomalous pulmonary venous connections were present, together with abnormal systemic venous connections. The results were unsatisfactory. Three of the four patients died. The only survivor had no pulmonary or systemic venous abnormalities. Severe impairment of pulmonary blood flow was one of the most important postoperative complications. The findings suggest that the complexities of rerouting the blood within the atria play an important role. The excess proportion of prosthetic material to atrial myocardium may result in excessive loss of contractile atrial myocardium and, probably equally significant, in a complex intra-atrial geometry of pathways that may cause a critical pressure gradient. The results clearly show that with an expanding horizon of the application of the Fontan principle, new pitfalls may arise which presently appear to be the prevailing factors limiting its success.