From the archives of the AFIP: pulmonary vasculature: hypertension and infarction

Pulmonary hypertension is the hemodynamic consequence of vascular changes within the precapillary (arterial) or postcapillary (venous) pulmonary circulation. These changes may be idiopathic, as in primary pulmonary hypertension or pulmonary veno-occlusive disease, but more commonly they represent a secondary response to alterations in pulmonary blood flow. The pulmonary and systemic bronchial circulations form broad anastomoses that largely prevent infarction except in settings of markedly elevated pulmonary venous pressure, underlying malignancy, or excessive embolic burden. Causes of precapillary pulmonary hypertension include long-standing cardiac left-to-right shunt, chronic thromboembolic disease, and widespread pulmonary embolism arising from intravascular malignant cells, parasites, or foreign materials. The classic radiologic features of precapillary pulmonary hypertension are central arterial enlargement, sharply pruned peripheral vascularity, and right-sided heart hypertrophy and chamber dilatation. Postcapillary pulmonary hypertension may develop secondary to focal venous constriction or to compromised pulmonary venous drainage due to left atrial neoplasia, mitral stenosis, or left ventricular failure. Radiologic manifestations of postcapillary pulmonary hypertension include prominent septal lines, small pleural effusions, and occasionally air-space opacities. In addition, radiologic evaluation of postcapillary pulmonary hypertension may demonstrate evidence of pulmonary arterial hypertension, secondary to the retrograde transmission of elevated pulmonary venous pressure across the capillary bed.

[Cri-du-chat syndrome. A case report]

We report a documented case in Senegal with cri-du-chat syndrome diagnosed in a 3 months old girl. Our patient benefited from clinical examination, ECG (15 derivations), chest X ray and standard laboratory tests. The cry has been recorded on a magnetic band. We performed also a pulsed-Doppler, two dimensional and TM echocardiography. Chromosomal analysis has been realized. These data are discussed and compared to the literature. At admission this patient presents characteristic cat like cry. At examination, there is a facial dysmorphy, important growth retardation and feeding dyspnea. Auscultation shows a 3/6 left sub-clavicular systolic murmur. Laboratory tests show anemia (hemoglobin = 7.8 g/dl). Chest x-ray showed a cardio-thoracic ratio at 0.61 with increased pulmonary vascular markings. ECG showed right ventricular hypertrophy. Echocardiography-Doppler revealed persistent ductus arteriosus (PDA). Chromosomal analysis shows deletion of the short arm of chromosome 5. After treatment with digitalis and diuretics there was an improvement of cardiac failure. Diagnosis of cri-du-chat syndrome is easy when characteristic cat-like-cry is present. Cardiovascular abnormalities are unfrequent in this syndrome (20% of the cases). They are dominated by ventricular septal defect and PDA. Hemodynamic failure and related growth retardation can lead to cardiac surgery.

Long-term invasive and noninvasive results of percutaneous balloon pulmonary valvuloplasty in children, adolescents, and adults

BACKGROUND

Short-term and mid-term results of percutaneous balloon pulmonary valvuloplasty (BPV) are well known. However, data documenting long-term effectiveness of BPV are scarce.

METHODS AND RESULTS

The long-term results of 62 patients were assessed by catheterization and Doppler echocardiography 1 to 10 years (mean 6.4 +/- 3.4) after BPV. Mean age of the patients was 13.5 +/- 10.5 years (range 9 months to 44 years). Twenty patients were 16 years of age or older. Right ventricular peak systolic pressure was systemic or suprasystemic in 72% of patients. A double-balloon technique was used in 29 patients. The balloon-to-pulmonary valve diameter ratio was 1.4 +/- 0.38 (range 1 to 1.8). Total systolic transpulmonary pressure gradient in excess of 50 mm Hg in all patients before BPV decreased from 98 +/- 40 to 32 +/- 23 immediately after BPV and to 19 +/- 9 mm Hg at follow-up (P <.001). Infundibular gradient increased from 8 +/- 10 to 14 +/- 24 mm Hg after BPV and fell to 1 +/- 4 mm Hg at follow-up (P <.01). In 16 patients it was >/=20 mm Hg and virtually disappeared spontaneously in all at follow-up. The valvar gradient fell from 93 +/- 39 to 19 +/- 11 (P <.001) and was 18 +/- 9 mm Hg at follow-up. It remained unchanged in 3 patients (range 36 to 45 mm Hg). In 3 (4.8%) other patients, a new gradient >35 mm Hg developed that was >/=50 mm Hg in all 3. Among 5 patients having dysplastic valves, 3 had a gradient >35 mm Hg. There were no predictors of a gradient >35 mm Hg at long-term follow-up by univariate or multivariate Cox proportional hazards analysis. Mild to moderate pulmonary regurgitation was present in 39% of patients. On electrocardiography, right ventricular hypertrophy decreased significantly in 90% of patients.

CONCLUSIONS

BPV as a treatment of typical pulmonic valve stenosis produces excellent long-term results. Restenosis is rare (4.8%) and occurs more frequently in patients with dysplastic valves. There is a constant spontaneous regression of associated infundibular obstruction.

Significance of a Q wave in lead I in the newborn

We present 11 healthy newborns whose electrocardiograms had a pure Q wave in lead I and who did not have a myocardial infarction clinically. We propose that in the healthy newborn, a pure Q wave in lead I may be due to increased right ventricular mass, not myocardial infarction.

Visualization of regional myocardial depolarization by tangential component mapping on magnetocardiogram in children

BACKGROUND

Tangential components to the body surface on magnetocardiography theoretically reflect regional myocardial current sources just below the gradiometer. The usefulness of tangential component mapping on magnetocardiography in determination of regional myocardial abnormalities has not been investigated in children.

METHODS

Twenty-six children with ventricular hypertrophy, including a child with a left ventricular diverticulum (aged 7 to 15), and age matched 22 healthy children (aged 7 to 15) were studied. Tangential components on magnetocardiography were measured using a newly-developed super-conducting quantum interference device system housed in a magnetically shielded room. Isomagnetic maps and current vector maps were constructed from the data obtained.

RESULTS

The peak magnetic fields and current dipoles were demonstrated to be located at the interventricular septum initially, and then were shifted to the anterior and inferior walls of the left ventricle and to the right ventricular outflow tract, successively. In patients with right ventricular hypertrophy whose systolic right ventricular pressure was over 60 mmHg, the peak magnetic fields were located in the right half with rightward directed current vectors throughout ventricular depolarization. In patients with left ventricular hypertrophy, the maximal magnetic fields during depolarization were shifted to the hypertrophic site, showing significantly stronger forces than those in healthy children (35.5+/-11.7 pT vs 26.5+/-11.9 pT, p < 0.01). In a patient with left ventricular diverticulum, two discrete depolarizing current dipoles were visualized. The mean time required in measuring MCGs among all subjects was 10 minutes.

CONCLUSION

The time course as well as the location of the regional electrical activities of the myocardium in children can be visualized, in a short time, as a two-dimensional projection to the frontal plane by tangential component mapping on magnetocardiography.

Electrocardiographic patterns of patients with echocardiographically determined biventricular hypertrophy

The numerous criteria proposed for the electrocardiographic (ECG) diagnosis of biventricular hypertrophy (BVH) suffer from inadequate correlative data. We used two-dimensional (2D) echocardiography to identify BVH and analyzed the ECG patterns in these patients. The study group had 69 such patients with BVH and the control group had 22 patients with isolated left ventricular hypertrophy (LVH) demonstrated by 2D echocardiography. The electrocardiograms were analyzed for the presence of established criteria used in the diagnosis of LVH and right ventricular hypertrophy (RVH). Of the 69 patients in the study group, 17 (25%) had ECG findings of BVH, 25 (36%) had LVH, and 14 (20%) had RVH. An S wave in V5/V6 of >7 mm was most the frequent finding in the 17 patients with BVH on the electrocardiogram. The sensitivity of ECG criteria for BVH was 24.6%, specificity was 86.4%, and positive predictive value was 85%. This study reemphasizes the difficulty of ECG diagnosis of BVH. The electrocardiogram has a low sensitivity but satisfactory specificity and positive predictive accuracy for BVH.

The DD genotype of the angiotensin converting enzyme gene is negatively associated with right ventricular hypertrophy in male patients with chronic obstructive pulmonary disease

The renin angiotensin system plays an important role in the development of pulmonary artery remodeling and right ventricular hypertrophy in hypoxia-induced pulmonary hypertension as may occur in patients with COPD. Several polymorphisms of genes encoding for components of the renin angiotensin system such as the M235T polymorphism in the angiotensinogen gene, the 287-base-pair insertion (I)/deletion (D) polymorphism at intron 16 of the ACE gene, and the A1166C polymorphism in the angiotensin II type 1 receptor gene have been associated with an increased risk of cardiovascular diseases. With respect to the pulmonary circulation, only limited data exist on possible associations between polymorphisms of these genes and pulmonary hypertension and/or right ventricular hypertrophy. The objective of the present study was to investigate a possible relationship between polymorphisms of the renin angiotensin system and electrocardiographic evidence of right ventricular hypertrophy in patients with COPD. We therefore determined the angiotensinogen (M235T), angiotensin converting enzyme (I/D), and angiotensin II type 1 receptor (A1166C) genotypes in 87 patients with severe COPD and correlated these data with electrocardiographic parameters of right ventricular hypertrophy. Thirty-one patients (36%) of 87 patients with COPD showed electrocardiographic evidence of right ventricular hypertrophy. In the male, but not in the female, subgroup, the angiotensin-converting enzyme DD genotype was negatively associated with electrocardiographic evidence of right ventricular hypertrophy (male: chi2 = 3.8, p = 0.05; female: chi2 = 0.05, p = 0.82). We found no associations between the investigated polymorphisms in the angiotensinogen and angiotensin II type 1 receptor genes and electrocardiographic evidence of right ventricular hypertrophy.

Radiology of the right ventricle

RV changes may be generalized into dilatation and hypertrophy. Increased preload results in ventricular dilatation. Increased afterload causes hypertrophy. Change in the shape of the RV resulting from increased afterload and myocardial hypertrophy induces tricuspid regurgitation, which superimposes changes of chamber dilatation onto those of hypertrophy. Sustained ventricular dilatation and hypertrophy frequently progresses to RV failure. In these cases, RV systolic function decreases in association with elevation of RV and right atrial diastolic pressure. Changes in the wall thickness and shape of the RV are variable, and depend upon the severity of the volume or pressure load presented, as well as its duration and rate of progression. Because the RV is an anterior cardiac structure, it occupies little of any heart border. Therefore, the sensitivity of plain film examination to RV disease is limited. Inferential diagnosis of RV disease can often be made based upon identification of other radiographic changes, notably the state of the pulmonary circulation, and the position of the heart in the chest. Conventional contrast right ventriculography may be used to assess the size and position of the RV, as well as associated acquired and congenital lesions that result in RV dysfunction. Due to the unusual shape of the RV cavity, however, and the unpredictable manner in which it dilates, accurate quantitative analysis by this technique is limited. Furthermore, the common association between RV disease and pulmonary hypertension limits the applicability of this imaging technique for evaluating patients with RV disease. Multiplanar MR imaging allows direct demonstration of changes in RV size and wall morphology. Furthermore, application of Simpson's rule to tomographic slices acquired at ventricular diastole and systole allows direct, accurate, and reproducible quantitative analysis of ventricular volume and myocardial mass, allowing radiographic assessment in patients for diagnosis, as well as longitudinally during medical management or after surgical treatment for congenital and acquired diseases that result in RV dysfunction.

Electrocardiographic and genetic evaluation of giant jungle fowl, broilers, and their reciprocal crosses following unilateral bronchus occlusion

Electrocardiography is useful as a noninvasive technique for detecting right ventricular hypertrophy in birds developing pulmonary hypertension (PH) and pulmonary hypertension syndrome (PHS, ascites). The objective of this study was to identify every aspect of the Lead II ECG wave form (amplitude or duration) that can be correlated with right ventricular hypertrophy [increased right:total ventricular weight ratios (RV:TV)] indicative of PH across a broad genetic background. Sham operations were conducted, or PH was induced by occluding one extrapulmonary primary bronchus in 14-d-old chicks produced from matings of broilers (B x B), Giant Jungle Fowl (J x J), and their reciprocal crosses (B x J and J x B). Standard three-lead electrocardiograms (ECG) were recorded on Days 28 and 42, and final necropsies were conducted to evaluate the incidence of ascites, confirm sex, and obtain ventricular weights for calculating RV:TV. Ascites did not develop in the J x J, and one each of the B x J and J x B chicks developed ascites; consequently, only data from birds that did not develop ascites were compared. Heart rate was recorded, and the following amplitudes and durations were measured or calculated for three consecutive wave cycles of the Lead II ECG: base of R to the peak of R (RbR), peak of R to base of S (RS), base of S to peak of R' (SR'), S, peak of R' to base of R' (R'R'b), and base of S to peak of T (ST). Differences between the ECG of sham and bronchus clamp groups were more prominent in B x B and B x J than in J x B, and bronchus occlusion did not affect the ECG, growth, or RV:TV ratios of J x J. In contrast, sex influences were more prominent in J x J and J x B than in B x J and B x B. These observations suggest a paternal pattern of inheritance for Lead II ECG wave forms, with crosses sired by broilers (B x B, B x J) exhibiting susceptibility to PH and few ECG differences related to sex, whereas crosses sired by Giant Jungle Fowl U x J, J x B) exhibited resistance to PH and numerous ECG differences related to sex.

[A case of interatrial communication in a dog]

A 4 month old female German Shepherd was presented for the work-up of a heart murmur that has been detected by the referring veterinarian. Clinical examination and thoracic radiography showed an enlargement of the right ventricle, and an increased pulmonary perfusion. Echocardiography showed an interatrial communication (atrial septum defect), and colour Doppler allowed the confirmation of a left to right shunt. The article discusses the diagnostic possibilities of this rare congenital cardiac malformation in the dog.

Specificity of electrocardiographic myocardial infarction screening criteria in patients with nonischemic cardiomyopathies

BACKGROUND

The 32-point, 54-criteria Selvester QRS scoring system has been successfully used to estimate the size of nonacute myocardial infarction (MI). Three criteria of the system have been shown to be sensitive for the identification of nonacute MI and specific in normal control subjects. The validity of the system has not been tested in patients with cardiomyopathy of nonischemic origin. The purpose of this study was to examine the electrocardiographs (ECGs) of patients with abnormal left ventricular function but no presence of coronary disease to determine the diagnostic specificity of the MI screening criteria subset of the Selvester QRS scoring system.

METHODS AND RESULTS

Six hundred ninety patients were considered. Exclusion criteria included age <10 years, cardiac transplantation, thrombolytic therapy, any angiographic evidence of coronary disease, left ventricular ejection fraction (LVEF) >60%, or history of myocardial revascularization. ECG exclusion criteria included left ventricular hypertrophy, right ventricular hypertrophy, left bundle branch block, right bundle branch block, ventricular pacing, left anterior fascicular block, left posterior fascicular block, ventricular preexcitation, and low voltage, because these confounding factors could mimic an infarct on the ECG. The 261 remaining patients were then examined for the presence of the MI screening criteria subset: (1) inferior location: Q > or =30 msec in aVF, (2) anterior location: either any Q or R< or =0.1 mV and < or =10 msec in V2, and (3) posterior location: R> or =40 msec in V1. Thirty-two of the 261 patients falsely met at least 1 of the 3 MI screening criteria, resulting in an overall specificity of 88% (vs 95% in normal control subjects, P=.0006). A specificity of 98% (n = 256) was achieved for the inferior MI screening criterion alone, whereas the anterior and posterior MI screening criteria alone achieved significantly lower specificities: 94% (n = 245) and 95% (n = 249), respectively. When the patient population was divided into LVEF <30% and LVEF > or =30%, no significant association was found between MI screening criteria and LVEF with specificities of 87% and 88%, respectively, for the 2 groups (P= .34).

CONCLUSIONS

The MI screening criteria subset is relatively specific in patients with nonischemic cardiomyopathy, falsely identifying only 12% with nonacute MI. However, this specificity is lower than the 95% achieved in normal subjects. Regional accumulation of scarring caused by cardiomyopathy could result in false-positive indication of MI in the present population. Another possibility could be that some patients could have hypertrophy of the myocardium insufficient to produce positive ECG criteria for left ventricular hypertrophy or right ventricular hypertrophy but sufficient to mimic infarction.

ECG observations in Tibetan and Han residents of Lhasa

In order to compare the prevalence of electrocardiographic (ECG) abnormalities suggestive of right ventricular hypertrophy in native and immigrant populations residing at high altitude, a retrospective review was undertaken of data obtained from a random survey of healthy volunteers and persons with chronic mountain sickness (CMS). All persons included in the survey were ambulatory volunteers from the general community who were evaluated at the Tibet Institute of Medical Science in Lhasa, where the elevation is 3,658 meters. The 74 residents of Lhasa, whose ECGs were studied, included 30 healthy Tibetan natives of Lhasa; 24 healthy Han (Chinese) immigrants, born at or near sea level, who had migrated to high altitude as children or adults; and 20 persons with symptoms of CMS. The ECGs of all subjects were reviewed for predetermined criteria suggestive of right ventricular hypertrophy, which were found to be present in 17% of healthy Tibetan natives, 29% of healthy Han immigrants, and 50% of CMS patients. The Han subjects who had migrated as children presented evidence of right ventricular hypertrophy more commonly than did adult immigrants. The overwhelming majority (90%) of persons with CMS were Han. Thus, the frequency of ECG abnormalities consistent with right ventricular hypertrophy was similar in healthy young Tibetan and Han men, but these abnormalities were less common in Tibetan natives than in Han who had migrated to high altitude as children or in CMS patients. The prevalence of ECG evidence of right ventricular hypertrophy increased with duration of high altitude residence among Han.

[Progressive cardiomyopathic lentiginosis]

We report on a 30-year-old man with progressive cardiomyopathic lentiginosis. This syndrome is first described by Polani and Moynahan 1972. They distinguish between the earlier described multiple lentigines syndrome, the LEOPARD syndrome (L-entiginosis, E-lectrocardiographic conduction defects, O-cular hypertelorism, P-ulmonary stenosis, A-bnormalities of genitalia, R-etardation of growth, D-eafness) and the progressive cardiomyopathic syndrome. The progressive cardiomyopathic syndrome is characterised by multiple symmetrical lentigines, hypertrophic obstructive cardiomyopathy and retardation of growth. All characteristics were present in our patient with only mild right ventricular hypertrophic cardiomyopathy.

[Value of classical and new criteria of electrocardiography in diagnosis of hypoxic cor pulmonale evaluated by hemodynamics tests]

Electrocardiogram is commonly used in the diagnosis of cor pulmonale in patients with chronic obstructive pulmonary disease (COPD). Pulmonary hemodynamics being the definite method for diagnosis the disease can be used to vary the ecg criteria for diagnosis cor pulmonale. After excluding patients with old myocardial infarction and with pulmonary wedge pressure > 12 mm Hg in 66 patients aged 65.2 with advanced COPD (FEV1 0.78 +/- 0.3 litre) pulmonary hemodynamics and ecg were performed at the same time. The signs of right ventricular hypertrophy were sought for using 3 sets of criteria: the World Health Organisation criteria, new compiled Lehtonen et al. Criteria and right ventricular precordial leads. WHO criteria had a specificity and sensitivity of 50% and 57.6%, the modified right precordial leads-53% and 64.5% and compiled Lehtonen's criteria -57% and 59% respectively. In 32 patients with mild pulmonary hypertension (20-29 mm Hg) sensitivity of WHO criteria was 46.8%, right precordial leads -51.6%, and Lethonen and co. Criteria -50%, in 10 patients with moderate pulmonary hypertension (30-39 mm Hg) 59%-62.5%-50%, in 9 patients with severe hypertension (> or = 40 mm Hg) 100%-100%-100% respectively. Our studies confirm the poor sensitivity and of ecg criteria for diagnosis of cor pulmonale (pulmonary hypertension) in COPD. However, in mild and moderate pulmonary hypertension, sensitivity of ecg diagnosis of cor pulmonale is improved if right modifieds precordial leads are used. New, compiled Lehtonen's criteria failed to improved diagnosis of diagnosis of cor pulmonale. All studied sets of criteria are highly sensitive in COPD patients with severe pulmonary hypertension.

On-line automated border detection for echocardiographic quantification of right ventricular size and function in children

Rapid, accurate assessment of right ventricular (RV) size is important for the management of children with congenital heart disease. The usefulness of the Acoustic Quantification system of automated border detection (ABD) and on-line quantification (AQ) for assessment of RV size was tested in 36 children. AQ data were compared to "corrected AQ" measurements (after correction for cavity areas erroneously included in the region of interest) required for AQ. Furthermore, the influence of necessary changes to gain settings was tested in "lateral gain control" (LGC) images obtained by removal of ABD overlays. All results were compared to conventional echocardiography (echo), and agreement with magnetic resonance imaging (MRI) RV areas was assessed. Systematic differences (+/-) limits of agreement with MRI (transverse plane) for conventional echo and AQ (apical four-chamber view) were as follows: end-diastolic -0.8 +/- 3.8 (conventional echo) versus -1.7 +/- 4.6 (AQ) cm2/m2 (p < 0.001); end-systolic -1.3 +/- 3.2 versus -4.9 +/- 5.8 (AQ) cm2/m2 (p < 0.001); fractional area change 7.8 +/- 17.0% versus 26.9 +/- 31.4% (AQ) (p < 0.001). Differences between conventional echo, LGC, and corrected AQ areas were not statistically significant. The best agreement between MRI and echocardiography was with conventional echo. We conclude that automated border detection of the RV can be performed successfully with the AQ system at a fixed point in the cardiac cycle. For adequate assessment of RV function manual corrections of online AQ results are still required, which results in an important reduction of the time gain of on-line quantification.

[Prognosis and outcome of idiopathic dilatation of the right atrium in children. A cooperative study of 15 cases]

Idiopathic dilatation is a rare abnormality corresponding to isolated aneurysmal dilatation of the right atrium, the outcome of which is not well known. Therefore a multicentric retrospective study was set up by the paediatric working group of the French Society of Cardiology recensing 7 boys and 8 girls who were diagnosed with this condition between 1971 and 1993. Ten of the children were asymptomatic and the diagnosis was suggested by the chest X-ray: one neonate had cardiac failure secondary to atrial tachycardia. The diagnosis has been facilitated by echocardiography since 1980. In this series, since 1993, four diagnoses were made antenatally. The outcome was variable : eight children are alive and well with follow-up periods ranging from 2 to 15 years (average 6 years) : four children have had cardiac arrhythmias : benign atrial extrasystoles (1 case), junctional reentrant tachycardia (1 case). The other two had more severe arrhythmias with flutter in a 7 year-old and one neonatal atrial tachycardia. The outcome was favourable with medical treatment. Three children underwent surgical atrial resection : the outcome has been good in these 3 cases with follow-up periods of 4, 13 and 18 years. This series shows that idiopathic dilatation of the right atrium is usually a well tolerated abnormality but unexpected complications may arise which can be severe such as arrhythmias, or which may be potentially threatening such as interatrial thrombosis. Management consists of either follow-up to diagnose complications which require appropriate treatment of systematic surgical correction as some authors suggest.

Biventricular systolic function and mass studied with MR imaging in children with pulmonary regurgitation after repair for tetralogy of Fallot

PURPOSE

To study biventricular systolic function and mass of the heart in young patients with residual pulmonary regurgitation who had undergone surgical correction of tetralogy of Fallot.

MATERIALS AND METHODS

Transverse gradient-echo magnetic resonance (MR) images covering both ventricles were obtained in 19 patients who had undergone corrective surgery for tetralogy of Fallot at the age of 1.5 years +/- 1 and in 12 age-matched control subjects. In addition, MR velocity maps of the pulmonary artery were obtained. Biventricular volumes, ejection fraction and myocardial mass, and pulmonary flow volumes were measured. Exercise tests were performed in 17 patients.

RESULTS

The right ventricular ejection fraction was lower (P < .001) and the right ventricular mass was higher (P < .0005) in patients than in control subjects; the left ventricular ejection fraction was lower (P < .0005) in patients and correlated statistically significantly with pulmonary regurgitation (r = -.68; P < .005). Exercise performance inversely correlated with pulmonary regurgitation (tau = -0.5; P = .01).

CONCLUSION

In children who undergo early surgical repair of tetralogy of Fallot, residual pulmonary regurgitation correlates with biventricular systolic dysfunction and diminished exercise capacity. Despite successful surgical correction, right ventricular hypertrophy may persist.

Two-year dynamics of vectorcardiography parameters in patients with primary pulmonary hypertension

VCG data (McFee--Parungao system) were obtained from 12 patients with primary pulmonary hypertension (PPH). During 2 years, VCG investigations were repeated from 2 to 5 times. Various VCG-parameters were analyzed. Space and horizontal QRS areas, projection of integra QRS vector to axis y and the sum of Rx and Sx were diagnostically most significant. Their values proved abnormal at the beginning of survey. In the course of observation, states of the right heart chambers together with VCG-parameter dynamics were investigated in every patient. States of the right cardiac chambers improved in 4 patients. In all of them the parameter turned to normal values. In two patients, during the monitoring time monotonous increase of parameters was observed, with the state of the right heart chambers declining. In 6 patients, state of right heart chambers appeared relatively stable. In these patients, values of all the parameters were either stable or insignificantly changeable around some mean values. Thus, the dynamics of VCG-parameters makes it possible to estimate adequately the states of the right cardiac chambers in PPH patients. (Tab. 1, Fig. 4, Ref. 4)

[Is the presence of right ventricular high intensity signals sufficient for the diagnosis of right ventricular dysplasia?]

The aim of this study was to assess "morphological" MRI data (spin-echo) compared with cine-MRI in 10 patients with documented right ventricular dysplasia and 10 normal controls. Data was acquired with a 0.5 Tesla superconductor magnet associating sequences of spin-echo and gradient echo (cine-MRI). An abnormal high intensity signal was observed in spin-echo in 9 out of the 10 patients. They were present on the anterior and sub-tricuspid walls of the right ventricle (8/10) and in the pulmonary infundibulum (8/10). A dyskinetic zone corresponding to the abnormal signals was detected in 8 patients. In the control group, only one subject had an abnormal high intensity signal and no dyskinesis could be detected. The association of high intensity signals and dyskinesis would seem to be very specific of right ventricular dysplasia. On the other hand, a high intensity signal alone may be observed in apparently normal subjects and would seem to be less specific.

[Vector-echocardiographic correlations in type B right ventricular hypertrophy]

The correlation between the right posterior surface of the QRS complex in the horizontal plane and the various parameters characterizing the right ventricle on TM and 2D echocardiography on left parasternal longitudinal sections and subcostal sections was investigated by the Chi-square independence test and Student's t test in 185 cases of heart disease due to various aetiologies. The right posterior surface (Octant III) of the QRS complex in the horizontal plane is independent of the diastolic thickness of the right ventricular posterior wall (RVPW); the diastolic thickness of the right ventricular anterior wall (RVAW); the right ventricular ejection fraction (RVEF); the systolic diameter and diastolic diameter of the right ventricle; the percentage thickening of the RVPW and the RVAW; and, finally, there is no significant relationship between the diastolic thickness of the RVPW and that of the RVAW. Its variance according to the presence or absence and the nature of an associated conduction disorder (RBBB, RIBBB, RBBB + LAHB, LAHB, LBBB, LIBBB or Kent) was not significant for a risk of error of 5% and 1%. The right posterior surface (Octant III) of the QRS complex in the horizontal plane is significantly correlated with the right ventricular mass (RVM), calculated from the diastolic thickness of the right ventricular posterior wall (RVPW): alpha < 0.001; according to a simplified formula: RVM g/m2 = (RVDD + 2 RVPW)3. The correlation between these last two quantitative parameters is borderline significant r = 0.11 t = 1.25, 0.20 < alpha < 0.30 according to a linear regression equation: y = 55.15-34.71 x; Po = 549 t = 1.48, increasing from 0 to 0.137 and decreasing beyond 0.137, linearity hypothesis: admissible, p = 0.04.