Tricuspid regurgitation in patients with repaired Tetralogy of Fallot and its relation to right ventricular dilatation

In a cohort of 56 school-aged children with repaired tetralogy of Fallot, significant (moderate to severe) tricuspid regurgitation was common (32% of patients) and was related to both tricuspid annulus dilatation and structural valve abnormalities that were potentially related to previous surgery. Even after adjusting for pulmonary regurgitation, tricuspid regurgitation was significantly correlated with right ventricular volume (r= 0.39, p = 0.009), suggesting that tricuspid regurgitation as well as pulmonary regurgitation may contribute significantly to progressive right ventricular dilatation in this population.

Decreased plasma neurohormones and improved cardiac performance after surgical treatment of chronic pulmonary embolism

The findings of this case report suggest that quantitative assessment of plasma neurohormones and magnetic resonance imaging functional parameters in patients with right ventricular pressure overload due to chronic pulmonary embolism might be used as indicators for right ventricular function before and after intervention. Monitoring of changes in these parameters may provide quantitative follow-up of right ventricular function in these patients.

Double-chambered right ventricle or sub-infundibular stenosis assessed by cardiovascular magnetic resonance

This paper presents magnetic resonance findings in four adults with double-chambered right ventricle or sub-infundibular stenosis, a condition that is treatable by surgery, but which can be difficult to assess echocardiographically. Four patients referred for cardiovascular magnetic resonance in the last 2 years were identified from CMR findings, although not necessarily from previous echocardiography, as having sub-infundibular stenosis. We used multislice spin echo imaging, cine imaging in oblique sagittal planes, and phase velocity mapping. We performed spin echo imaging of a post-mortem heart without known structural abnormality to illustrate right ventricular myocardial morphology. Results in patients showed evidence of sub-infundibular muscular obstruction separating the hypertrophied inlet and apical portions of the right ventricle from a thin-walled, unobstructed infundibular region in each case, with a systolic jet originating at least 15 mm beneath the unstenosed pulmonary valve. In addition to previously described structural components contributing to stenosis--enlargement and/or displacement of the septomarginal trabeculation, septoparietal trabeculations or the moderator band--CMR suggested additional components: a right ventricular papillary muscle in one, an anteriorly bulging aortic sinus in one, and hypertrophied muscular ridges of the parietal wall of the right ventricle. Even in this small group of patients, the causes of sub-infundibular stenosis appeared to be varied and multi-factorial. The abilities of magnetic resonance to give unrestricted, multi-planar views of right ventricular anatomy, movement and flow make it well suited for diagnosis and characterization of sub-infundibular stenosis, especially in adults.

Jarcho-levin syndrome associated with a complex congenital heart anomaly

Jarcho-Levin syndrome is characterized by "crab-like" rib cage deformity and multiple vertebral anomalies that cause respiratory failure. Reports of complex congenital heart defects with this syndrome are rare. We describe a female infant with this syndrome and a complex congenital heart defect and review the literature. Congenital heart defects are occasionally complicated by Jarcho-Levin syndrome. Heart defects involving heterotaxic morphology should be included as one of the important clinical features of this syndrome.

[The electrocardiogram in primary pulmonary hypertension]

Primary pulmonary hypertension is a rare disease characterized by a rise of arterial pressure in the pulmonary artery without a known cause. The authors define, based on a case-history, the etiopathogenesis of the disease, its diagnosis and approach to treatment. They analyze the contribution of ECG examination for detection of right ventricular hypertrophy and for monitoring the therapeutic success with the finding above all of repolarization changes in the right precordium. The patient had a transplantation of the lungs.

[Importance of the ECG for evaluation of severity of pulmonary embolisms]

OBJECTIVE

To evaluate whether it is possible on the basis of ECG examination to judge the haemodynamic impact of pulmonary embolism.

METHOD

To compare by retrospective analysis of hospital documentation of patients at the medical department the assessed ECG changes with the echocardiographic finding of pulmonary hypertension and right ventricular dilatation. As positive an ECG finding was evaluated involving changes of the ST-T segment in VI-V4, S1Q3T3 negative or right bundle branch block (RBBB). As a positive echocardiographic finding the authors evaluated the size of the right ventricle above 30 mm or the shape of the acceleration curve in the outflow tract of the right ventricle corresponding to pulmonary hypertension.

RESULTS

The authors analyzed 179 patients with clinically diagnosed pulmonary embolism during the period from Jan. 1 1996 till Dec. 31 2000. A positive ECG finding was recorded in 103 patients, i.e. 57.5%. Echocardiographic examination was made in 112 and 65 of them had a positive ECG. An echocardiographic finding of pulmonary hypertension or dilatation of the right ventricle was recorded in 92 patients. In case of positivity of at least one ECG finding an ECG sensitivity of 62% and specificity of 60% was found. In case of changes in the ST-T segment in V1-V4 the sensitivity and specificity was 47% and 70% resp., for S1Q3T3 negative 27% and 80% resp. and PRT block 25% and 90% resp.

CONCLUSIONS

The absence of ECG changes does not rule out serious pulmonary embolism. The finding of typical ECG changes is very frequently associated with pulmonary hypertension, right ventricular dilatation and a serious haemodynamic finding.

[Electrocardiographic signs of right ventricular overload useful in improving diagnosis of chronic thromboembolic pulmonary hypertension (CTE-PH) in patients with chronic exertional dyspnea]

The early recognition of chronic thromboembolic pulmonary hypertension (CTE-PH) is troublesome because of "honey moon" period with chronic dyspnea on exertion as the only one symptom. To find if routine electrocardiography may be useful in improving the diagnosis, value of right ventricular overload (RVO) signs in recognition echocardiographically determined chronic pulmonary hypertension (CPH) and angiographically confirmed CTE-PH in 90 consecutive patients hospitalized due to chronic exertional dyspnea was studied. CPE was found in 76.5% and CTE-PH in 33% of those patients, at least one of twelve founded electrocardiographic signs of RVO was present in 50% patients. The most frequently occurred signs: negative T wave in lead V1-V6, right axis deviation and pulmonale P wave as well as 9 other occurred at frequency below 20% signs of RVO had low to medium sensitivity and negative predictive value and 80-90% positive predictive value for diagnosing CPE and 90-100% positive predictive value for diagnosing CTE-PH. It was concluded that in patients with chronic exertional dyspnea electrocardiographic signs of RVO may be useful in initial diagnosing of CPH and CTE-PH in particular.

[ECG based diagnosis of right ventricular hypertrophy in patients with chronic obstructive bronchitis]

Two mathematical models developed on the basis of a discriminant analysis of the evidence obtained in examination of 84 patients with chronic obstructive bronchitis (COB) are proposed in early diagnosis of right ventricular hypertrophy (RVH) by ECG readings in COB patients. Application of hierarchic classification model is recommended for diagnosis of RVH in screening. The probability model is intended for follow-up of COB patients.

[ECG in ventricular hypertrophy]

The electrophysiological criteria for the diagnosis of ventricular hypertrophies, in the light of the sequence of ventricular depolarization and repolarization, are described. Hypertrophy of the right ventricle due to sustained systolic overloading can be global or segmental. In the first case, the magnitude and manifestation of the main vectors resulting from depolarization of this ventricle, i.e., IIs, IIr and IIIr, are increased. In the second case, the magnitude and manifestation of only some vectors resulting from its depolarization are increased; for example, vector IIr (right parietal) in the most frequent type of Fallot's tetralogy and vector IIIr (right basal) in chronic corpulmonale of obstructive origin. Left ventricular hypertrophy, which is generally of global type (aortic stenosis, systemic arterial hypertension), induces an increase in magnitude and manifestation of all the main vectors resulting from depolarization of this ventricle: I (first septal), II (left parietal) and III (left basal). But the left ventricular hypertrophy can also be of segmental type; for example, in idiopathic hypertrophic cardiomyopathy, in which the manifestation of an anteroseptal vector usually predominates. Biventricular hypertrophies produce different electrocardiographic patterns, depending on the preponderance of right or left electromotive ventricular forces. An example of electrocardiographic findings in biventricular hypertrophy is presented. It corresponds to an 18 year-old woman with a large patent ductus arteriosus compressing the left inferior laryngeal nerve, which produced a cardio-vocal syndrome. The patient had pulmonary and systemic hypertension and arterial hyposaturation. The surgical treatment of the patent ductus arteriosus normalized the pulmonary pressure as well as the arterial saturation.

Using 12-lead ECG and synthesized VCG in detection of right ventricular hypertrophy with terminal right conduction delay versus partial right bundle branch block in the pediatric population

In pediatric electrocardiogram (ECG) analysis, mild right ventricular hypertrophy (RVH) and especially mild RVH with terminal right conduction delay (RVHtcd) are often confused with partial right bundle branch block (PRBBB). This is problematic for computer ECG analysis algorithms and even for most experienced pediatric cardiologists. This study was designed to achieve better classification of mild RVHtcd and PRBBB by combining the 12-lead synthesized vectocardiogram (VCG) transverse plane measurements with scalar ECG measurements. Pediatric ECGs used in the study were recorded with 15 leads and a 500 Hz sampling rate at the Lucile Salter Packard Children's Hospital, Stanford University Medical Center. Out of 4,200 ECGs collected consecutively over a period of 18 months, 447 RVH, 335 RBBB and 589 Normal were interpreted by expert pediatric cardiologists, and were included in the study. Statistical comparison of ECG and VCG measurements were done in stratified ECG sets (412) that have a visually indistinguishable waveform pattern, 117 RVHtcd, 96 PRBBB and 199 normal, showed significant differences in initial and terminal vectors in the transverse plane. The mean angle of the initial vector was anterior (57.2 degrees +/- 41.8) in the normal group, left anterior in the PRBBB group (34.4 degrees +/- 39.5) and in the RVHtcd group (31.9 degrees +/- 41.0) and. The mean angle of the terminal vector was right anterior (158.3 degrees +/- 36.8) in the PRBBB group, rightward (179.7 degrees +/- 29.9) in the RVHtcd group and right posterior (212.6 degrees +/- 37.8) in the normal group. These are clearly applicable features for a classification algorithm. Significantly improved classification results were obtained from a new algorithm using combined ECG and VCG measurements versus an existing algorithm. The limitation of this study stems from the unavailability of a more reliable gold standard. It may be necessary to used body surface potentials obtained with a large number of electrodes to accurately differentiate the study groups.

Paradoxical embolism. An old but, paradoxically, under-estimated problem

The theoretical model of paradoxical embolism requires the presence of four parameters, namely, arterial embolism, venous thrombus, abnormal intracardiac communication and right-to-left shunt. Many aspects, however, of this well known entity are under consideration; diagnosis is often difficult to be established and the long term efficacy of preventive measures is undefined. We comment on a case report of recurrent paradoxical embolism with popliteal vein thrombosis and patent foramen ovale, and we briefly review the literature.

Right ventricular cardiomyopathy accompanied by protein-losing enteropathy and chylous effusion

Severe right-side heart failure developed in a 47-year-old Japanese woman who suffered from hypoalbuminemia and a massive right side chylous pleural effusion. She had been diagnosed as having protein-losing enteropathy with right ventricular cardiomyopathy. Autopsy showed congenital anomalies of the lymph ducts and abnormal deposition of fibrous and fatty tissue in the right ventricular myocardium. The clinical and pathological findings are consistent with the nonarrythmogenic form of the arrythmogenic right ventricular dysplasia.

Echocardiographic features of the right heart in sleep-disordered breathing: the Framingham Heart Study

The effect of sleep-disordered breathing (SDB) on right heart structure and function is controversial. Studies of patients referred for evaluation of possible sleep apnea have yielded conflicting results, and the impact of SDB on the right heart has not been investigated in the general population. We examined the echocardiographic features of subjects with SDB at the Framingham Heart Study site of the Sleep Heart Health Study. Of 1,001 polysomnography subjects, 90 with SDB defined as a respiratory disturbance index (RDI) score > 90th percentile (mean RDI = 42) were compared with 90 low-RDI subjects (mean RDI = 5) matched for age, sex, and body mass index. Right heart measurements, made without knowledge of clinical status, were compared between groups. The majority of the subjects were male (74%). After multivariable adjustment, right ventricle (RV) wall thickness was significantly greater (p = 0.005) in subjects with SDB (0.78 +/- 0.02 cm) than in the low-RDI subjects (0.68 +/- 0.02 cm). Right atrial dimensions, RV dimensions, and RV systolic function were not found to be significantly different between subjects with SDB and the low-RDI subjects. We conclude that in this community-based study of SDB and right heart echocardiographic features, RV wall thickness was increased in subjects with SDB. Whether the RV hypertrophy observed in persons with SDB is associated with increased morbidity and mortality remains unknown.

Angiotensin-converting enzyme inhibitor preserves p21 and endothelial nitric oxide synthase expression in monocrotaline-induced pulmonary arterial hypertension in rats

BACKGROUND

Pulmonary arterial hypertension (PAH) is associated with structural changes in the pulmonary vasculature characterized by the proliferation of cellular components of the vessels. ACE inhibitor (ACEI) may have beneficial effects in treating PAH, but its precise mechanism of action in the remodeling process is unclear. p21 is a cyclin-dependent kinase inhibitor that may have a protective role in this process by inhibiting cellular proliferation. Endothelial nitric oxide synthase (eNOS) has also been shown to be protective by its vasodilatory effect. Therefore, we investigated whether expression of p21 and eNOS was modulated by ACEI treatment in a rat model.

METHODS AND RESULTS

Monocrotaline (MCT) was administered to 2 groups of Sprague-Dawley rats fed a high-cholesterol diet, ie, one group received MCT concomitantly with enalapril treatment (MCT(+)/ACEI(+) rats), and the other group did not receive enalapril (MCT(+)/ACEI(-) rats). After 5 weeks, MRI showed right ventricular hypertrophy in MCT(+)/ACEI(-) rats. MCT(+)/ACEI(+) rats showed a preserved right ventricular morphology. Isolated pulmonary perfusion studies showed that ACEI significantly upregulated NO production, as measured by nitrite levels. Addition of N-methyl-D-glucamine dithiocarbamate-Fe solution, an NO-trapping agent, reversed the basal vasodilatory effect of ACEI in the pulmonary vasculature. Immunoblot analysis showed decreased p21 and eNOS expression in the lung in MCT(+)/ACEI(-) rats, whereas their expression was preserved with enalapril treatment.

CONCLUSIONS

ACEI suppresses the development of MCT-induced PAH in rats. The mechanism of action might involve the preservation of p21 and eNOS expression. Both p21 and endothelium-derived NO appear to have protective roles in the development of PAH.

Time course of structural adaptations in chronic AV block dogs: evidence for differential ventricular remodeling

To determine the nature and time course of biventricular hypertrophy and concomitant electrical and mechanical changes after creation of complete atrioventricular block (CAVB), six adult dogs (22–30 kg) were subjected to serial magnetic resonance imaging (MRI) and electrocardiography. After 6 days of CAVB, left ventricular (LV) mass, ejection fraction (EF), and Q-T time at a paced rhythm of 60 beats/min were already significantly increased. Maximal values were reached within 14–21 days of CAVB: LV mass, from 116 ± 11 to 143 ± 12 g; right ventricular (RV) mass, from 40 ± 3 to 55 ± 6 g; EF, from 68 ± 6% to 86 ± 5%; and Q-T time, from 285 ± 25 to 330 ± 35 ms, all P < 0.05. Cardiac output returned to baseline at day 14. End-diastolic wall thickness increased only in the RV, in which angiotensin type 1 (AT1) receptor mRNA expression was significantly greater. The autopsy correlated well with the MRI results ( r = 0.98, P≤ 0.01). In conclusion, electrophysiological, mechanical, and structural adaptation processes after bradycardia-induced volume overload develop rapidly and are completed within 3 wk. The degree of hypertrophy was greater in the RV, which was associated with an increase in AT1receptor mRNA.

Diagnostic dilemma

In those issues in which our regular Case of the Month does not appear, The Green Journal will present a Diagnostic Dilemma-an electrocardiogram or radiograph, or both, with a brief case history-as a challenge for our readers to solve. The correct answer appears on page 742. If you would like to contribute a Diagnostic Dilemma, please submit a high-quality copy of the ECG or radiograph with a brief synopsis (<250 words) of the case to editorial office of the American Journal of Medicine.

The crochetage pattern in electrocardiograms of pediatric atrial septal defect patients

OBJECTIVES

To test the sensitivity and specificity of the crochetage pattern (a notch near the apex of the R wave in electrocardiographic inferior limb leads) in the pediatric electrocardiogram for detecting patients with a secundum atrial septal defect.

PATIENTS AND METHODS

Electrocardiograms from 82 consecutive preoperative pediatric patients with a secundum atrial septal defect confirmed by two-dimensional echocardiography were reviewed for evidence of right ventricular hypertrophy and the crochetage pattern. These electrocardiograms were compared with 244 consecutive preoperative controls consisting of patients with echocardiographically proven patent foramen ovale, ventricular septal defect, pulmonary stenosis, tetralogy of Fallot and patients with normal echocardiogram studies.

RESULTS

The electrocardiographic crochetage pattern was observed in 31.7% of preoperative patients with a secundum atrial septal defect in at least one inferior limb lead. The specificity of the crochetage pattern for the detection of a secundum atrial septal defect was high when present in all three inferior limb leads (greater than 92%). The crochetage pattern in at least one lead in secundum atrial septal defects shows no association with incomplete right bundle branch block (c2(1)=0.80, not significant), and thus these two findings together do not improve the detection of an atrial septal defect.

CONCLUSIONS

The sensitivity and specificity of the electrocardiographic crochetage patterns in at least one inferior limb lead in echocardiographically proven secundum atrial septal defects are 31.7% and 86.1%, respectively. The electrocardiographic crochetage or notching pattern in inferior limb leads has a high specificity for atrial septal defects in the pediatric population.