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Biomedical subjects

C Pernot

Publications and source records attributed to C Pernot.

At least 19 recordsLinked to original sources
PubMed1992

Right ventricular overload and induced sustained ventricular tachycardia in operatively "repaired" tetralogy of Fallot.

The aim of the study was to evaluate the main predictors of the inducibility of sustained ventricular tachycardia (VT) in patients with repaired tetralogy of Fallot. Thirty-five patients (age 12 +/- 6 years) underwent right-sided cardiac catheterization, echocardiography, radionuclide angiography and ventricular stimulation; 10 had (group 1) and 25 had no (group 2) sustained VT. Group 1 patients were significantly older at the time of surgery and had longer follow-up periods (7 +/- 3 vs 4 +/- 4 years, p less than 0.02; and 12 +/- 4 vs 5 +/- 2 years, p less than 0.001, respectively). Right ventricular (RV) systolic pressure, end-systolic and end-diastolic normalized RV volumes were higher in group 1 (48 +/- 14 vs 38 +/- 11 mm Hg, p less than 0.05; 1.23 +/- 0.2 vs 0.86 +/- 0.17, p less than 0.001; and 2.35 +/- 0.37 vs 1.70 +/- 0.22, p less than 0.001, respectively). RV end-diastolic pressure, left ventricular and RV ejection fractions were similar in the 2 groups. A stepwise discriminant analysis was made to predict patients with inducible sustained VT (group 1): Time period from surgery to follow-up (p less than 0.001), normalized RV end-systolic volume (p less than 0.002) and RV systolic pressure (p = 0.01) were higher in group 1 and allowed classification of 90% of patients in group 1 and 96% in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Systemic artery-pulmonary vein fistula without sequestration.

Fistulae between an artery arising from the aorta and a pulmonary vein associated with absence of a branch of the pulmonary artery, but without anomalies of the bronchial tree, are exceedingly rare. We report a case in a child who presented with a continuous vascular murmur and developed heart failure due to the left-left shunt. Left lobectomy was performed and showed that the entire left lower lobe was occupied by a huge arteriovenous fistula between an artery stemming from the aorta and the pulmonary veins.

Aorta↗
PubMed1990

A simplified normalized ejection phase index measured by Doppler echocardiography for the assessment of left ventricular performance.

Although useful for the assessment of directional changes in contractility in individual patients, resting peak aortic blood velocity is of limited value for differentiating among patients with different levels of basal cardiac function. A dimensional analysis based on fluid dynamics shows that peak aortic blood velocity is not only generated by the contracting myocardium but also reflects the convective acceleration of blood from the left ventricle to the aorta. The reduction of cross-sectional area from the midleft ventricle to the aorta at the time of peak aortic blood velocity generates the convective acceleration. Accordingly, a higher convective acceleration due to left ventricular (LV) enlargement as observed in cardiomyopathy may explain why peak aortic blood velocity can be maintained as normal although myocardial contractility is depressed. This study tested the hypothesis that peak aortic blood velocity normalized by the ratio of midleft ventricle to aortic cross-sectional areas might provide a reliable index of LV performance. Nine normal control subjects and 25 patients undergoing catheterization were studied by M-mode, 2-dimensional and Doppler echocardiography. The normalized peak velocity measured noninvasively showed a high correlation with angiographic ejection fraction (r = 0.90, p less than 0.0001). Peak aortic blood velocity and the ratio of midleft ventricle to aortic cross-sectional areas alone correlated less well with ejection fraction (r = 0.76 and r = 0.75, p less than 0.0001, respectively). Furthermore, peak aortic blood velocity showed a significant overlap between patients with normal and those with abnormal LV function, whereas normalized peak aortic blood velocity was a better discriminator.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Role of previous angina pectoris and collateral flow to preserve left ventricular function in the presence or absence of myocardial infarction in isolated total occlusion of the left anterior descending coronary artery.

The aim of this study was to determine whether previous angina pectoris and collateral circulation influenced myocardial function after isolated coronary occlusion. In 58 consecutive patients, coronary angiography showed a complete isolated occlusion of the left anterior descending coronary artery; 43 patients (74%) had previous myocardial infarction. Duration of previous angina pectoris was defined as the time from the first ischemic symptom to the date of myocardial infarction or of coronary angiography in the absence of myocardial infarction. Left ventricular ejection fraction was measured on the 30 degrees right anterior oblique projection of the left ventricular angiogram. Collateral circulation was graded as follows: none or filling limited to side branches (group 1) and partial or complete filling of the epicardial arterial segment (group 2). Group 2 (40 patients) had higher ejection fraction (57 vs 38%; p less than 0.0001) and longer duration of previous angina pectoris (11 vs 0.1 months; p less than 0.002) than group 1 (18 patients). A longer duration of previous angina pectoris probably allows collateral development before coronary occlusion in 1-vessel coronary artery disease, thereby limiting myocardial damage.

Angina Pectoris↗
PubMed1990

Value of esophageal pacing in evaluation of supraventricular tachycardia.

Esophageal stimulation was performed in 40 patients who had spontaneous paroxysmal supraventricular tachycardias (SVTs). The purpose of this study was to look for the most sensitive stimulation protocol and criteria that would help to define the mechanism of reentry. In 20 patients (group I) atrial pacing up to second-degree atrioventricular block was performed under control conditions and isoproterenol, and SVT was induced in 14 patients (70%), 11 in the control state and 3 while receiving isoproterenol. In 20 patients (group II) atrial pacing and programmed atrial stimulation using 1 and 2 extrastimuli delivered at 2 cycle lengths (600 and 500 ms) was performed in the control state and while receiving isoproterenol. SVT was induced in all patients, in 13 patients in the control state and in 7 while receiving isoproterenol. Programmed stimulation always induced SVT and was the only method capable of tachycardia induction in 14 patients. The mechanism of SVT could be established in 91%. The measurement of the ventriculoatrial interval was the most useful sign to define the site of reentry. Occurrence of a bundle branch block helped to delineate the mechanism in 4 patients. When a positive P wave in V1 preceded the esophageal atrial electrocardiogram, it suggested that there was reentry through a left-sided accessory atrioventricular connection in 6 patients. SVT could always be induced by programmed atrial stimulation in the control state and under isoproterenol. The location of the P wave in V1 compared to the ventriculogram and the esophageal electrocardiogram helped to define the mechanism of tachycardia.

Bundle-Branch Block↗
PubMed1990

[Frequency of the onset of supraventricular tachyarrhythmias as a function of underlying heart disease].

The prevalence of inducible ventricular arrhythmias is related to the underlying pathology. This study was undertaken to determine the prevalence of supraventricular tachyarrhythmias (SVT), atrial tachycardia, flutter or fibrillation, sustained for over 30 seconds. Programmed atrial stimulation was used to deliver 1 or 2 extrastimuli during sinus and paced rhythm in 230 subjects without obvious cardiac disease (149 without and 81 with spontaneous SVT) and 432 patients with documented cardiac pathology (407 without and 25 with spontaneous SVT). The incidence of inducible SVT with respect to that of spontaneous SVT and in relation to cardiac pathology was as follows: (table; see text) The prevalence of inducible SVT in patients without spontaneous SVT was related to the type of pathology: (table; see text) These results show that in patients with spontaneous SVT the induction of the arrhythmia was facilitated by the presence of underlying cardiac pathology (sensitivity increasing from 67% to 88%). In patients without spontaneous SVT, the nature of the underlying disease was related to the prevalence of inducible SVT, the risk being major in SA block, right ventricular dysplasia and mitral valve prolapse (60-80%) and moderate in dilated CMP and myocardial infarction (35 to 40%).

Adult↗
PubMed1990

[Cardiac rhabdomyoma in children and Bourneville's tuberous sclerosis].

Cardiac rhabdomyomas are rare congenital tumours resulting from an early dysembryoplastic disorder of organogenesis. They are generally benign hamartomas which may be the first manifestation of a phakomatosis, tuberous sclerosis (TS) (Bourneville disease), present in over half of cases. The cases of 11 children with cardiac rhabdomyomas are reported. All of them also had extracardiac lesions of TS. Their ages ranged from 1 day to 6 years of age. In one case, the diagnosis was made antenatally by foetal echocardiography. The clinical expression may be very serious when there are hemodynamic disturbances resulting from an obstructive syndrome (N = 3) or arrhythmias (N = 2). Nevertheless, the cardiac evolution is usually favorable (N = 9) in contrast to the neuropsychiatric outcome which is generally catastrophic (N = 8). The diagnosis is made by two-dimensional echocardiography and magnetic resonance imaging. Surgical resection of the tumours is reserved for forms complicated by cardiac failure due to intracardiac obstruction (N = 2) of life-threatening resistant arrhythmias. Genetic counseling should be directed towards prevention of TS because it is transmitted in an autosomal dominant mode. However, most of the cases are sporadic. Echocardiography should be systematic in all children with TS and is also recommended for members of their families, even those apparently unaffected, in order not to miss paucisymptomatic forms of TS.

Adolescent↗
PubMed1990

[Relations of the duration of pre-existing angina pectoris, collateral circulation and left ventricular function after isolated coronary occlusion with or without myocardial infarction].

The aim of this retrospective study was to determine the relationship between the duration of preceding angina pectoris, collateral circulation and left ventricular function after isolated coronary occlusion with or without myocardial infarction. Coronary angiography of 138 consecutive patients showed isolated and complete occlusions of the left anterior descending (58 patients) or right coronary artery (80 patients). One hundred and four patients had myocardial infarction with (Group A, n = 21) or without (Group B, n = 83) preceding angina pectoris and 34 had angina without myocardial infarction (Group C). The left ventricular ejection fraction was measured by ventriculography in the 30 degrees right anterior oblique projection. The collateral circulation was assessed by coronary angiography and evaluated as follows: no flow or flow limited to collateral branches (subgroup 1) and partial or complete filling of the epicardial arterial segment (subgroup 2). In the global population the left ventricular ejection fraction was higher and the duration of preceding angina pectoris was longer in the subgroups with a well developed collateral circulation. There was no difference in ejection fraction between Groups A and B (presence of myocardial infarction), on the other hand, within each of the groups, a good collateral circulation (subgroup 2) was associated with a significantly higher ejection fraction. Group C (without infarction) patients had better ejection fractions than Groups A or B, especially when the collateral circulation was poorly developed. Within Group C, the quality of the collateral circulation did not seem to affect the ejection fraction. The left ventricular ejection fraction is lower in patients with isolated coronary occlusion and myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1990

[Induction of supraventricular tachycardia (paroxysmal junctional tachycardia and atrial tachycardia) by esophageal stimulation].

Transesophageal stimulation is tending to replace endocavitary electrophysiological studies in the investigation and treatment of supraventricular tachyarrhythmias. The aim of this study was to determine the sensitivity of this technique in the evaluation of paroxysmal junctional tachycardia (PJT) and atrial tachycardia (AT). Fifty-eight patients with these arrhythmias (PJT, n = 23; AT, n = 35) were investigated under basal conditions and then during Isoproterenol infusions with a protocol using incremental atrial stimulation and programmed atrial stimulation delivering one and two extra-stimuli on two paced rhythms (400-600 ms). It was possible to induce the arrhythmia in the 23 patients with PJT either under basal conditions (n = 16) or during Isoproterenol (n = 7). A reentrant mechanism was suggested in 22 patients by the following findings: position of the auriculogramme with respect to the ventriculogramme, presence or absence of a delaying branch block, situation and morphology of the P wave in lead V1 compared with atrial activation recorded by the esophageal catheter. Atrial tachycardia was induced in 26 patients (74 per cent), 19 under basal conditions, 6 with Isoproterenol and once after carotid sinus massage. As a conclusion, we can say that the sensitivity of transesophageal stimulation is the same as for endocavitary stimulation.

Adolescent↗
PubMed1989

Doppler echocardiographic measurement of low velocity motion of the left ventricular posterior wall.

A new noninvasive method using pulsed Doppler echocardiography was developed to assess left ventricular (LV) posterior wall motion dynamics. Seventeen normal subjects and 23 patients undergoing cardiac catheterization were prospectively studied. The sample volume was placed within the LV posterior wall endocardium just apical to the mitral valve sulcus using a posteriorly angulated low parasternal view. The wall filter was set at 100 Hz to record the low velocities of the LV posterior wall motion. The Doppler signal was morphologically similar to the rate of change of the LV posterior wall endocardium excursion obtained by a digitized M-mode echocardiogram, and showed 3 major waves: a systolic wave (S), an early diastolic wave (E) and a late diastolic wave (A). The peak velocities of LV posterior wall endocardium excursion were also determined by M-mode echocardiographic technique. We found a significant linear correlation between peak E-wave velocity and M-mode peak diastolic endocardial velocity (r = 0.90, p less than 0.001) and between peak S-wave velocity and M-mode peak systolic endocardial velocity (r = 0.81, p less than 0.001). M-mode peak systolic endocardial velocity showed an important overlap between control subjects and patients with normal and patients with abnormal LV posterior wall motion on the angiogram. In contrast, peak S-wave velocity was a better discriminator, and a peak S-wave velocity less than 7.5 cm/s was associated with abnormal LV posterior wall motion with an 83% sensitivity, 100% specificity and 95% accuracy. In patients with coronary artery disease but normal systolic LV posterior wall motion and normal global systolic LV function, peak S-wave velocity was not different when compared to control subjects. Peak E-wave velocity and E/A were significantly lower than in control subjects (p less than 0.01) and peak A-wave velocity was greater (p less than 0.01). In conclusion, these data suggest that pulsed Doppler echocardiography can be used for the direct analysis of LV posterior wall instantaneous low velocities and appears to be more informative than M-mode technique for systolic measurements. Thus, detection of abnormal LV posterior wall diastolic motion by pulsed Doppler echocardiography may, upon additional confirmation, be used as a new noninvasive method to gain insight into global LV diastolic performance.

Adult↗
PubMed1989

A new Doppler method of assessing left ventricular ejection force in chronic congestive heart failure.

A noninvasive method using Doppler echocardiography was developed to determine the force exerted by the left ventricle in accelerating the blood into the aorta. The value of this new Doppler ejection index in the assessment of left ventricular (LV) performance was tested in 36 patients with chronic congestive heart disease undergoing cardiac catheterization and in 11 age-matched normal control subjects. The 36 patients were subgrouped into 3 groups based on angiographic ejection fraction (LV ejection fraction greater than 60, 41 to 60 and less than or equal to 40%). According to Newton's second law of motion (force = mass X acceleration), the LV ejection force was derived from the product of the mass of blood ejected during the acceleration time with the mean acceleration undergone during that time. In patients with LV ejection fraction less than or equal to 40%, LV ejection force, peak aortic velocity and mean acceleration were severely depressed when compared with the other groups (p less than 0.001). In patients with LV ejection fraction of 41 to 60%, LV ejection force was significantly reduced (22 +/- 3 kdynes) when compared with normal subjects (29 +/- 5 kdynes, p = 0.002) and with patients with LV ejection fraction greater than 60% (29 +/- 7 kdynes, p = 0.009); peak velocity and mean acceleration did not differ between these 3 groups. The LV ejection force showed a good linear correlation with LV ejection fraction (r = 0.86) and a better power fit (r = 0.91). Peak aortic blood velocity and mean acceleration showed less good linear correlations with LV ejection fraction (r = 0.73 and r = 0.66, respectively). The mass of blood ejected during the acceleration time also showed a weak linear correlation with LV ejection fraction (r = 0.64). An LV ejection force less than 20 kdynes was associated with a depressed LV performance (LV ejection fraction less than 50%) with 91% sensitivity and 90% specificity. Thus, these findings suggest that LV ejection force is a new Doppler ejection phase index that appears to be more accurate than peak aortic blood velocity and mean acceleration for the assessment of systolic LV function.

Aged↗
PubMed1989

[Survival in primary dilated cardiomyopathy as a function of tobacco smoking. A retrospective study].

In order to determine the influence of tobacco smoking on the course and long-term prognosis of idiopathic dilated cardiomyopathy, we conducted a retrospective study of 111 patients (95 men and 16 women, mean age 45.5 +/- 8.1 years) who had undergone cardiac catheterization between January 1970 and December 1979 and had been followed up for 6 to 16 years. The criteria of inclusion was diffuse hypokinesia of the left ventricle with an ejection fraction of 50 per cent or less, normal coronary arteriography and cardiomyopathy of unknown origin. The overall mortality rates at 1, 5 and 10 years were 10, 50 and 66 per cent respectively, and the main predictive factor was the left ventricular ejection fraction. Forty-six per cent of these patients were smokers, 19 per cent were non-smokers and 35 per cent had undetermined smoking habits. A univariate analysis showed a favourable predictive effect of smoking on survival (P less than 0.01), and this was confirmed by the statistical hypothesis of maximum bias for patients with undetermined smoking habits. On multivariate analysis, this predictive effect was superseded by the left ventricular ejection fraction, but after stratification of the sample according to the mean value of ejection fraction (30 per cent), the predictive value of smoking reappeared clearly in the group with a less than 30 per cent ejection fraction (P less than 0.003).

Adult↗
PubMed1989

Return to work after percutaneous transluminal coronary angioplasty: a continuing problem.

Earlier studies have shown that return to work following PTCA is frequent; however PTCA is now performed in patients with more extensive coronary artery disease. The present study was designed to compare the vocational outcome of patients who underwent PTCA in 1980-1982 with that of patients who underwent the procedure in 1985. From 1980 to 1982, 53 of 73 consecutive patients who were employed before PTCA returned to work (73%). Return to work was related to primary success of the procedure (85% vs 40%, P less than 0.01) age (46.1 +/- 7.9 vs 49.3 +/- 6.6 years, P less than 0.05) and clinical status at follow-up (72% feeling well or very well vs 30%, P less than 0.01). In 1985, although the primary success rate had increased to 89%, the overall rate of return to work in the 91 patients employed before PTCA was 64%. The decrease was particularly striking for patients with primary success of the procedure (64% vs 85%, P less than 0.01). The patients in the 1985 group had greater incidences of previous myocardial infarction (40% vs 11%, P less than 0.01) and multivessel coronary disease (43% vs 8%, P less than 0.01); however, these factors were not related to subsequent return to work. In contrast, the age of the patients, which was an important determinant of work resumption, was significantly higher in the 1985 patients (49.9 +/- 7.3 vs 46.4 +/- 9.1 years, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

The tall R wave in lead V1 in posterior myocardial infarction: a reciprocal sign or a His-Purkinje conduction disturbance?

The significance of the tall R wave in lead V1 with an R/S ratio greater than or equal to 1 in posterior myocardial infarction (PMI) was investigated in 28 patients during programmed electrical stimulation. The patients had been admitted with acute PMI documented by electrocardiogram and proven by enzymatic increase. Electrophysiological study was performed 3 weeks after acute PMI. In 17 of the 28 patients (group 1), the tall R wave in V1 disappeared during stimulation: In 13 of them a premature atrial extrastimulus was responsible for an abrupt normalization of QRS complex in V1 related to an increase in AH or HV interval. In the 4 remaining patients the disappearance of the tall R wave in V1 was related to a sinus pause. In 14 patients of group 1, a different prematurity in atrial stimulation induced a right or left bundle branch block (BBB). In 11 of the 28 patients (group 2) the tall R wave in V1 was unchanged but a premature atrial extrastimulus induced a right BBB in 5 patients and a left BBB in 6. In conclusion, the normalization of QRS complex in lead V1 during atrial stimulation or alterations in cycle length suggests that the tall R wave in V1 in PMI is not a simple reciprocal sign of leads V8 V9. Its association with different varieties of BBB and changes in AH or HV intervals could suggest a relationship with a His-Purkinje conduction disturbance in some patients.

Adult↗