Right atrial diverticulum associated with the Wolff-Parkinson-White syndrome in a child

A child with Wolff-Parkinson-White syndrome showed large right atrial diverticulum overlying the right ventricle and the right coronary artery at CT angio with right atrial appendage as a separate structure. The accessory pathway was located at the diverticulum. Catheter ablation was not regarded feasible and surgery was indicated. A broad muscular connection between the right atrium and ventricle was interrupted by transsection and cryoablation as confirmed by disappearance of preexcitation. This precisely CT documented case represents a rarely reported right atrial diverticulum posing a high risk of life-threatening arrhythmias.     

Different distribution of abnormal endocardial electrograms within the right atrium in patients with sick sinus syndrome

Background—Prolonged and fractionated right atrial endocardial electrograms are characteristic of paroxysmal atrial fibrillation (idiopathic or associated with sick sinus syndrome). The distribution of these abnormal atrial electrograms within the right atrium and the way it is related to the likelihood that patients with sick sinus syndrome will develop paroxysmal atrial fibrillation was studied.

Methods—Endocardial catheter mapping of the right atrium during sinus rhythm was performed in 41 control patients with normal sinus node function and without paroxysmal atrial fibrillation, in 33 patients with sick sinus syndrome but without tachycardia, and in 27 patients with sick sinus syndrome and paroxysmal atrial fibrillation (group 3). The bipolar electrograms were recorded at 12 sites in the right atrium and an abnormal atrial electrogram was defined as lasting ≥100 ms and/or showing eight or more fragmented deflections.

Results—1195 atrial endocardial electrograms were assessed and quantitatively measured. In patients with sick sinus syndrome and paroxysmal atrial fibrillation 54% of the abnormal atrial electrograms were recorded from the high right atrium, 28% from the mid right atrium, and 18% from the low right atrium. However, in patients with sick sinus syndrome without tachycardia 78% of the abnormal atrial electrograms were recorded from the high right atrium and 22% from the mid right atrium. No abnormal electrograms were recorded from the low right atrium.

Conclusions—In patients with sick sinus syndrome without tachycardia abnormal atrial electrograms generally came from the high right atrium but in patients with sick sinus syndrome and paroxysmal atrial fibrillation abnormal atrial electrograms were more widely distributed in the right atrium. In patients with sick sinus syndrome the greater the extent of the compromised atrial muscle, the greater the likelihood that paroxysmal atrial fibrillation will develop.

     

Right atrial diverticulum in an adult patient

Right atrial diverticula are rare clinical findings and thus this possibility is usually omitted in the differential diagnosis of right atrial pathologies. Only 105 cases of right atrial anomalies were reported in medical journals in years 1955-1998, of which only 13 cases referred to a single diverticulum of the right atrium. The presented case is a 65-year-old patient with a right atrial diverticulum whose presence was confirmed intra-operatively.     

Giant right atrial diverticulum: an unusual cause of Wolff-Parkinson-White syndrome.

A case of a giant right atrial diverticulum associated with neonatal supraventricular tachycardia is reported. The electrocardiogram in sinus rhythm showed pre-excitation that may have been caused by the right atrial diverticulum adhering to the right ventricle.     

Diverticulum of the right ventricle

We report the case of a 38-year-old woman who underwent cardiac catheterization because of cyanosis from birth. This study revealed a right ventricular cavity hypoplasia, an atrial septal defect, and a diverticulum originated from the free right ventricular wall. Ventricular diverticuli, especially those in the right ventricle, are very rare malformations, usually associated with other cardiac defects. The right ventricular diverticulum is generally non-symptomatic, diagnosed by chance, and does not usually require surgical treatment.     

Optimal pacing modes after cardiac transplantation: is synchronisation of recipient and donor atria beneficial?

Objective—To investigate the response of the transplanted heart to different pacing modes and to synchronisation of the recipient and donor atria in terms of cardiac output at rest.

Design—Doppler derived cardiac output measurements at three pacing rates (90/min, 110/min and 130/min) in five pacing modes: right ventricular pacing, donor atrial pacing, recipient-donor synchronous pacing, donor atrial-ventricular sequential pacing, and synchronous recipient-donor atrial-ventricular sequential pacing.

Patients—11 healthy cardiac transplant recipients with three pairs of epicardial leads inserted at transplantation.

Results—Donor atrial pacing (+11% overall) and donor atrial-ventricular sequential pacing (+8% overall) were significantly better than right ventricular pacing (p < 0·001) at all pacing rates. Synchronised pacing of recipient and donor atrial segments did not confer additional benefit in either atrial or atrial-ventricular sequential modes of pacing in terms of cardiac output at rest at these fixed rates.

Conclusions—Atrial pacing or atrial-ventricular sequential pacing appear to be appropriate modes in cardiac transplant recipients. Synchronisation of recipient and donor atrial segments in this study produced no additional benefit. Chronotropic competence in these patients may, however, result in improved exercise capacity and deserves further investigation.

     

No incremental benefit of multisite atrial pacing compared with right atrial pacing in patients with drug refractory paroxysmal atrial fibrillation

OBJECTIVE—To evaluate the incremental antifibrillatory effect of multisite atrial pacing compared with right atrial pacing in patients with drug refractory paroxysmal atrial fibrillation paced for arrhythmia prevention alone.
METHODS—In 20 of these patients (mean (SD) age 64 (8) years; 14 female, six male), a single blinded randomised crossover study was performed to investigate the incremental benefit of one month of multisite atrial pacing compared with one month of right atrial pacing. Outcomes included the number of episodes of paroxysmal atrial fibrillation, their total duration obtained from pacemaker Holter memory, and quality of life using a cardiac specific questionnaire (the modified Karolinska questionnaire).
RESULTS—Comparing right atrial with multisite atrial pacing, there was no significant change in either the number of paroxysmal atrial fibrillation episodes (mean (SD): right atrial pacing 77 (98) episodes v multisite pacing 52 (78) episodes, NS) or their total duration (right atrial, 4.8 (5.4) days v multisite, 6.3 (9.8) days, NS). Quality of life scores compared with baseline status were equally improved by either pacing strategy (mean percentage improvement: right atrial, 38%, p = 0.003; multisite, 44%, p = 0.003). There was no significant difference in life scores comparing the two pacing modes.
CONCLUSIONS—Multisite atrial pacing has no incremental antiarrhythmic effect compared with right atrial pacing in patients paced for drug refractory paroxysmal atrial fibrillation. Quality of life is equally improved with either pacing strategy, with no differences between them.


Keywords: multisite atrial pacing; atrial fibrillation; pacing     

Congenital diverticulum of the right ventricle associated with coarctation of aorta, atrial and ventricular septal defect and ductus.

Congenital right ventricular muscular diverticula are extremely rare and are usually associated with other congenital cardiac anomalies, (in half of the cases tetralogy of Fallot). They functionally behave like an accessory ventricular chamber which contracts synchronously with the normal ventricles.Less than 30 patients with a right ventricular diverticulum have been reported in literature. An apical right ventricular diverticulum occurs in patients with thoraco-abdominal midline defects or abnormalities of the cardiac position([1]). However, an antero-superior diverticulum is usually associated with other congenital cardiac defects, such as a ventricular septal defect, tetralogy of Fallot, double outlet right ventricle and pulmonary stenosis([2--9]).We report an 11-year-old boy with an antero-superior diverticulum of the right ventricle associated with a coarctation of aorta, ductus arteriosus, and atrial and ventricular septum defects. To the best of our knowledge, such an association has not been reported before.     

Accidental detection of a giant right atrial aneurysm in an asymptomatic infant

We present a 4-month old infant boy accidentally detected to have cardiomegaly on a chest radiograph, and on further investigation discovered to have a giant right atrial aneurysm and a secundum atrial septal defect. Congenital right atrial aneurysm or diverticulum is a rare anomaly, usually presenting with atrial or supraventricular tachycardia. Previously reported patients did not have any associated congenital heart defect. Although asymptomatic our patient needs close follow-up, and surgical resettion of the aneurysm and closure of the atrial septal defect in view of potential complications.     

Comparison of the acute effects of pacing the atrial septum, right atrial appendage, coronary sinus os, and the latter two sites simultaneously on the duration of atrial activation

OBJECTIVE—To compare the acute effects of right atrial appendage, atrial septal, coronary sinus os, and dual site pacing on the duration of atrial activation.
METHODS—20 patients with a variety of cardiac conditions underwent an intracardiac electrophysiological study. Electrograms were recorded from the right atrial appendage and at multiple sites within the coronary sinus. The duration of atrial activation was measured during pacing at the right atrial appendage, atrial septum, and coronary sinus os, and also during dual site stimulation.
RESULTS—The duration of atrial activation with atrial appendage pacing was notably longer (p < 0.001) than with dual site, septal, or coronary sinus os pacing, but there were no significant differences in atrial activation times between these latter three pacing modes. When stimulating the atria at a cycle length of 500 ms, the mean (SD) duration of atrial activation was 145 (37) ms for right atrial appendage pacing, 93 (26) ms for dual site pacing, 96 (28) ms for septal pacing, and 98 (28) ms for coronary sinus os pacing.
CONCLUSIONS—Assuming that the duration of atrial activation is an important determinant of predisposition to paroxysmal atrial fibrillation, atrial septal pacing or coronary sinus os pacing would appear to offer the same advantage as dual site pacing without the additional complexities associated with the latter pacing mode.


Keywords: atrial septal pacing; dual site pacing; atrial activation; atrial fibrillation     

Congenital right atrial diverticulum, atrial septal defect within the oval fossa, and complex pulmonary valvar obstruction in an infant with chromosome 8(p23.1) deletion

We describe an unusual right atrial aneurysm, occurring with progressive obstruction of the right ventricular outflow tract and increasing cyanosis, in a nine-month-old boy with chromosome 8(p23.1) deletion. Surgical resection of the diverticulum, and relief of the right ventricular obstruction, was successful, although impairment of right ventricular compliance persists after 19 months follow-up.     

A novel method for transcatheter closure of atrial septal defect within an aneurysm of the fossa ovalis: double sheath technique

An aneurysm of the fossa ovalis is frequently associated with an atrial septal defect. Intervention with transcatheter closure of such defects may be difficult since it bears the risk of inadvertent deployment of the device with both umbrellas in the right or left atrium. A novel technique for the closure of such multiperforated aneurysms of the fossa ovalis, which allows central positioning and controlled deployment of the device, is reported.


Keywords: fossa ovalis; aneurysm; atrial septal defect; transcatheter closure     

Cystic tumour of the atrioventricular nodal region: report of a case successfully treated with surgery

A case is reported of a 59 year old woman who presented with palpitations. Electrocardiographic studies revealed atrial fibrillation and atrioventricular block. Echocardiography and magnetic resonance imaging showed a right atrial cystic mass attached to the interatrial septum. The patient underwent surgical excision of the mass. Histopathological findings were of a cystic tumour of the atrioventricular nodal region. This is the second report of this condition diagnosed antemortem and treated successfully with surgical excision.


Keywords: atrioventricular block; cystic tumour; excision     

Left ventricular filling characteristics in pulmonary hypertension: a new mode of ventricular interaction

Objective—To examine the effects of pulmonary hypertension on left ventricular diastolic function and to relate the findings to possible mechanisms of interdependence between the right and left sides of the heart in ventricular disease.

Design—A retrospective and prospective analysis of echocardiographic and Doppler studies.

Setting—A tertiary referral centre for both cardiac and pulmonary disease.

Patients—29 patients with pulmonary hypertension (12 primary pulmonary hypertension, 10 pulmonary fibrosis, five atrial septal defect (ASD), and two scleroderma) were compared with a control group of 10 patients with an enlarged right ventricle but normal pulmonary artery pressure (six ASD, one after ASD closure, one ASD and pulmonary valvotomy, one tricuspid valve endocarditis and repair, and one pulmonary fibrosis). None had clinical or echocardiographic evidence of intrinsic left ventricular disease.

Main Outcome measures—M mode echocardiographic measurements were made of septal thickness, and left and right ventricular internal cavity dimensions. Doppler derived right ventricular to right atrial pressure drop, and time intervals were measured, as were isovolumic relaxation time, and Doppler left ventricular filling characteristics.

Results—The peak right ventricular to right atrial pressure gradient was (mean (SD)) 60 (16) mm Hg in pulmonary hypertensive patients, and 18 (5) mm Hg in controls. The time intervals P₂ to the end of the tricuspid regurgitation, and P₂ to the start of tricuspid flow were both prolonged in patients with pulmonary hypertension compared with controls (115 (60) and 120 (40) ν 40 (15) and 45 (10) ms, p values <0·001). Pulmonary hypertensive patients commonly had a dominant A wave on the transmitral Doppler (23/29); however, all the controls had a dominant E wave. Isovolumic relaxation time of the left ventricle was prolonged in pulmonary hypertensive patients compared with controls, measured as both A₂ to mitral valve opening (80 (25) ν 50 (15) ms) and as A₂ to the start of mitral flow (105 (30) ν 60 (15) ms, p values <0·001). The delay from mitral valve opening to the start of transmitral flow was longer in patients with pulmonary hypertension (30 (15) ms) compared with controls (10 (10) ms, p < 0·001). At the time of mitral opening there was a right ventricular to right atrial gradient of 12 (10) mm Hg in pulmonary hypertensive patients, but this was negligible in controls (0·4 (0·3) mm Hg, p < 0·001).

Conclusions—Prolonged decline of right ventricular tension, the direct result of severe pulmonary hypertension, may appear as prolonged tricuspid regurgitation. It persists until after mitral valve opening on the left side of the heart, where events during isovolumic relaxation are disorganised, and subsequent filling is impaired. These effects are likely to be mediated through the interventricular septum, and this right-left ventricular asynchrony may represent a hitherto unrecognised mode of ventricular interaction.

     

Total anomalous pulmonary venous return: apropos of an unusual case]

A case is reported in which the entire pulmonary venous return was abnormal, being retro-cardiac. Unusual features were the age at which the abnormality was discovered (14 years), and the anatomical type of abnormality of pulmonary venous return. The return effectively emptied into a posterior cavity which was "a diverticulum of the right atrium" which had a wide communication with the "normal" right atrium, which in turn communicated with the left atrium by a highly placed Ostium Secundum. The muscular septum which separated the highly placed auricle of the left atrium and the "diverticulum" was removed, and vertical partitioning allowed a right and left atrial cavity to be reconstituted. The post-operative progress was uneventful.     

Arrhythmias after the Fontan procedure

Objective—To study the determinants and outcome of arrhythmias after the Fontan type operation.

Design—Retrospective analysis of data in patients operated on between 1972 and 1986 (follow up 5–19 years (mean 12 years)).

Patients—All 60 patients undergoing a Fontan type procedure at the National Heart Hospital, London, during the study period (mean age (SD) 12·3 (6·8) years).

Results—Postoperative arrhythmias occurred in 34 patients (57%), and 11 (58%) of 19 early postoperative deaths (within seven days) were related to arrhythmias. Early arrhythmias occurred in 19 (32%) patients of whom 11 (58%) died. All patients with early atrial fibrillation and His bundle tachycardia died and only preoperative atrial fibrillation recurred early. There was a higher incidence of early arrhythmias, which were less well tolerated, in double inlet single ventricle patients (9/19) than in those with tricuspid atresia (8/37). There were no other preoperative determinants of early arrhythmias or deaths from early arrhythmia. Late (after seven days) arrhythmias occurred in 15 (37% of hospital survivors). They had higher right atrial (RA) pressures both early and late after operation and had lower ventricular ejection fractions late after operation. Of those with atrial arrhythmias 86% had RA obstruction and 57% had an RA thrombus or pulmonary embolism at presentation; this was also confirmed in two patients in whom late sudden deaths occurred. Atrial fibrillation early after reoperation for RA obstruction was fatal. The actuarial arrhythmia free survival for hospital survivors was 60% at 10 years.

Conclusions—Early postoperative arrhythmias were poorly tolerated, particularly atrial fibrillation and His bundle tachycardia. Previous atrial fibrillation was a relative contraindication to this procedure. Late postoperative arrhythmias were associated with higher RA pressures measured both early and late after operation and worse late ventricular function. Late arrhythmias may be the first manifestation of RA obstruction, which must be sought. RA thrombus was common in patients with atrial arrhythmias and should be treated early with anticoagulants.

     

Cardiac rhythm and symptomatic arrhythmia in right atrial isomerism

Background The conduction system in right atrial isomerism may be complicated by the presence of paired sinus nodes and twin atrioventricular nodes. With a large cohort of infants and children with right atrial isomerism, we sought to investigate the nature of atrial rhythm, its prevalence, factors predisposing patients to symptomatic cardiac arrhythmia, and the relation of arrhythmia to long-term morbidity and mortality. Methods Standard 12-lead baseline electrocardiograms were performed in 110 infants and children with right atrial isomerism at a median age of 1 day, and their clinical records were reviewed. The type, timing, and precipitating factors of symptomatic cardiac arrhythmia that occurred in 15 patients, among a cohort of 85 patients who had or were awaiting surgical interventions, were noted. Results All patients except 1 had a sinus rhythm with intact atrioventricular conduction. Of these, 87% (95/109) had single P-wave morphology, whereas 13% (14/109) had multiple P-wave morphologies. For patients with a single P-wave morphology, the frontal P-wave axis was between 0 degrees and 90 degrees in 62% (59/95), 90 degrees and 180 degrees in 23% (22/95), and superior in 15% (14/95). There was no relation between either P-wave axis or morphology and cardiac anatomy. Symptomatic cardiac arrhythmia occurred in 15 of 85 patients (18%); 11 of the 15 patients had supraventricular tachycardia, and 1 patient each had atrial tachycardia, atrial flutter, ventricular tachycardia, and congenital complete heart block. The arrhythmias occurred before surgery in 4 patients, early after surgery in 5 patients, and late after surgery in 6 patients. Although 3 of the 7 patients who died suddenly had a history of symptomatic arrhythmia, arrhythmia was the documented cause of mortality in only 1 of the 32 fatalities (3.1%). Freedom from arrhythmia at 1, 5, 10, 15, and 20 years was 93% ± 3%, 86% ± 4%, 80% ± 6%, 73% ± 9%, and 48% ± 15% (mean ± SE), respectively. No risk factors for symptomatic arrhythmia were identified by means of logistic regression. Conclusions The atrial pacemaker varies in location within and between patients with right atrial isomerism. Although symptomatic cardiac arrhythmias are not uncommon, they do not seem to relate to the overall high mortality rate and occurrence of sudden death in this patient group. Nonetheless, detailed assessment and aggressive management of cardiac arrhythmias once they occur are warranted because of the precarious single ventricular hemodynamics. (Am Heart J 2002;144:159-64.)     

Contrast transesophageal echocardiography in diagnosing congenital enlargement of the right atrium--a case report

Congenital malformation of the right atrium or the coronary sinus is rare, and cases are classified into 1 of the following 4 categories: (1) congenital enlargement of right atrium, (2) single diverticulum, (3) multiple diverticula of the right atrium, and (4) diverticulum of the coronary sinus. This report presents a 63-year-old man with cardiomegaly and no chest symptoms. A chest radiograph revealed an enlarged cardiac silhouette with a prominent right heart border. Although a transesophageal echocardiography revealed marked enlargement of the right atrium, neither further anomaly nor massive regurgitation was observed. The systolic pulmonary artery pressure derived from the peak velocity of mild tricuspid regurgitation was 38 mm Hg. Secondary enlargement of the right atrium due to atrial septal defect or pulmonary venous connection anomaly was deemed negligible by use of transesophageal contrast echocardiography, and primary enlargement of the right atrium was confirmed. Transesophageal echocardiography using ultrasound contrast was determined to be feasible for diagnosing congenital malformation of the right atrium.     

Transient atrial mechanical dysfunction (stunning) after cardioversion of atrial fibrillation and flutter

Background Conversion of atrial fibrillation (AFib) and flutter (AFlt) to sinus rhythm results in a transient mechanical dysfunction of atria (atrial stunning). Methods used as a means of assessing atrial stunning, atrial stunning after conversion of atrial fibrillation/flutter, and the cause, mechanisms, determinants of the extent, and drugs affecting atrial stunning were examined. Methods Studies on the subject, identified through a comprehensive literature search, were thoroughly evaluated. Results and Conclusions Left atrial (LA) stunning has been reported with all modes of conversion of AFib/AFlt to sinus rhythm. The incidence of LA stunning is 38% to 80%. Spontaneous echocardiographic contrast, LA appendage (LAA) flow velocities and emptying fraction, transmitral inflow velocity of atrial wave (A-wave), time-velocity integral of A-wave, and atrial filling fraction have been used as means of assessing LA stunning. The data on right atrial (RA) stunning are limited, but parallel findings have been reported in the right atrium. Atrial stunning does not develop after the unsuccessful attempts of cardioversion or on delivery of electric current to the heart without AFib/AFlt, and it is a function of the underlying AFib/AFlt manifesting at the restoration of sinus rhythm. Tachycardia-induced atrial myopathy and chronic atrial hibernation are suggested mechanisms. Duration of preceding AFib/AFlt, atrial size, and underlying heart disease are determinants of the extent of atrial stunning. Verapamil, dofetilide, and acetylstrophenathidine have been shown to attenuate or protect from atrial stunning in animal or small human studies. A comprehensive knowledge of atrial stunning would be helpful in selecting the patients for, and the duration of, anticoagulation therapy after cardioversion. (Am Heart J 2002;144:11-22.)     

Atrioventricular valve diverticulum--an unusual congenital malformation

A previously unreported congenital malformation was noted in an infant with right atrial isomerism ("asplenia syndrome"). The superior bridging leaflet of a common atrioventricular valve was attached to a band of muscular tissue spanning the atrioventricular junction. A large ventricular diverticulum extended into the substance of this band, possibly due to traction during fetal life.