Biomedical subjects
Publications and source records attributed to J Valty.
The authors report a case of severe constrictive pericarditis occurring 6 weeks after coronary bypass surgery and in the absence of any other predisposing factor. The diagnosis was confirmed by CT scan and cardiac catheterisation which showed signs of a diastole. The patient died despite early surgical reoperation because of the severity of the pericardial fibrosis.
UNLABELLED: The aim was to find an objective indicator in order to evaluate white coat effect (WE). The first hour average values after placing an ambulatory blood pressure recorder (15 mn intervals) were compared to those of the 4 following hours of diurnal activity. A first hour systolic arterial blood pressure (SBP 1H) increase of 10 mmHg or more was considered as an ambulatory WE positive (AWE+) and was compared to clinical WE (CWE). CWE+ was observed in 78 pts and AWE+ in 72 among a group of 172 unselected pts referred for hypertension. RESULTS: the correlation between AWE and CWE is weak (r = 0.49) but significant (p < 0.001). There was no difference between the two groups in age, sex, clinical blood pressure, heart rate or ambulatory BP after the first hour (table). There was a significant difference in SBP between the 2 groups (p < 0.001) during the first hour only. [table: see text] CONCLUSION: Ambulatory blood pressure recording is able to recognize and evaluate the white coat effect. We suggest to consider independently the first hour of each recording and to compare it with the mean pressure measured during the period of diurnal activity.
The authors report the case of puerperal thrombosis of the right ovarian vein complicated by recurrent small pulmonary emboli in a 32 year old woman. The clinical features of this rare condition are reviewed. The echographic, angiographic and CT scan and magnetic resonance imaging abnormalities are described. The authors underline the value of non-invasive radiological investigations for early diagnosis. The patient was rapidly improved by medical therapy with antibiotics and heparin.
The renin-angiotensin and cardiac natriuretic systems were studied by measuring plasma renin activity, plasma concentrations of active renin, angiotensinogen, atrial natriuretic hormone and urinary cyclic GMP in 37 patients with moderate to severe cardiac failure. The plasma sodium and osmolality were chosen as markers of hydroelectrolytic imbalance and plasma concentrations of préalbumin and retinol-binding protein as indicators of the degree of hepatocellular dysfunction. Plasma renin activity (PRA) plasma concentration of active renin, atrial natriuretic hormone and urinary cyclic GMP were higher in patients in NYHA Class IV than in those in Classes II-III, whilst plasma sodium, angiotensinogen, prealbumin and retinol-binding protein concentrations were lower in Class IV patients than in patients in Classes II-III. The plasma angiotensinogen concentrations were negatively correlated with PRA (r = -0.41, p less than 0.02), active renin (r = -0.45, p = 0.005), the atrial natriuretic factor (r = -0.36, p less than 0.05) and positively correlated with prealbumin (r = 0.54, p less than 0.001) and retinol-binding protein (r = 0.60, p less than 0.0001). In NYHA Class IV patients the decreased circulating renin substrate led to an underestimation of plasma concentrations of active renin by measurement of PRA. On the other hand, direct radio-immunometric measurement of active renin allows true estimation of circulating active renin, independently of plasma angiotensinogen concentrations and thereby reliably reflects activation of the renin system. The serum sodium was negatively correlated with active renin (r = -0.66, p less than 0.0001) in these patients not receiving converting enzyme inhibitors.(ABSTRACT TRUNCATED AT 250 WORDS)
Abnormalities of myocardial metabolism during acute rejection may be due to ischemia to primary metabolic changes related to rejection. An experimental study of heterotopic cardiac transplantation in the rat was undertaken to study myocardial mitochondrial oxidation during acute rejection. The receivers were Lewis rats and the donors Fischer (FL: allograft) or Lewis (LL: isograft) rats. The oxygen consumption of the mitochondria (VO2m) isolated from the transplanted and native hearts was measured by oxygraphy six days after transplantation. Using maleate and glutamate substrates, the VO2m of transplanted hearts was significantly lower than that of native hearts in the two groups of rats (FL, p less than 0.01; LL, p less than 0.01). In addition, the VO2m of FL allograft transplanted hearts was significantly lower than in the LL rats (30 +/- 9 vs 100 +/- 15 nanoatoms of oxygen/min.mg/prot, p less than 0.01) as was the VO2m of the native hearts (FL: 106 +/- 23 vs LL: 164 +/- 26, p less than 0.02). The respiratory control ratio (RCR) was significantly lower in the transplanted than in the native hearts in both the FL and LL groups (p less than 0.05 and p less than 0.01 respectively). The comparison of the RCR in the two groups (FL vs LL) showed no significant difference for transplanted or native hearts. Electron microscopy of transplanted (rejected or not) and native hearts showed no morphological abnormality of the mitochondria. The lower VO2m of the allograft group indicates a disturbance in the mitochondrial respiratory pathway during acute rejection.(ABSTRACT TRUNCATED AT 250 WORDS)
Explore the source record for details and available documents.
The authors report a case of ventricular tachycardia (VT) induced by theophylline toxicity in a patient with ischaemic heart disease complicated by left ventricular failure and chronic asthma. Two episodes of VT were reduced by intravenous injection of magnesium chloride. The aggravating role of a moderate magnesium deficiency is suggested by the synergy of hypomagnesemia and theophylline on intracellular calcium fluxes contributing to an accumulation of intracytoplasmic calcium, a situation which has been shown experimentally to generate delayed after depolarisations. The respective roles of the correction of the metabolic deficiency and of the specific antiarrhythmic action related to the calcium blocking effect of magnesium salts at cellular level are discussed.
Left ventricular outflow tract (LVOT) obstruction has been observed in elderly patients with concentric hypertrophic hypertensive cardiomyopathy (HHCM) and no significant valvular disease or regional wall motion abnormalities. In order to determine whether nitroglycerin (NTG) can increase the intraventricular obstruction, we performed echocardiographic (echo) and doppler studies, before and during administration of sublingual NTG (0.8 mg). Twenty patients (n = 20) with long-standing hypertension (19 women and 1 man, mean age 78 +/- 8 yr, mean duration of hypertension 13 +/- 10 yrs were examined. The clinical findings in 17 patients were: angina 5 (29%), dyspnea 9 (53%), syncope or malaise 4 (23%). Electrocardiographic criteria of left ventricular hypertrophy was present in 4 patients and an increased cardio-thoracic ratio (greater than 0.5) in 9 cases. The following echo parameters were determined using M-mode echocardiograms: LV end-diastolic (LVID) and systolic diameter (LVIS), fractional shortening (FS), ventricular septum thickness (IVST), posterior wall thickness (PWT) and the ratio ISVT/PWT (less than 1.3 in all patients). LVM could be calculated in 15 patients and was corrected for body surface area (LVMI). Pulsed and continuous wave Doppler study showed a characteristic late-peaking velocity waveform. We localized the elevated velocities in the LVOT and determined before and during administration of NTG: LVOT peak velocities (V) and peak intraventricular gradients (G) using simplified Bernoulli equation. Results were as follows: [table: see text] Mild mitral regurgitation was observed in 14 patients (70%) and mitral annular calcifications in 11 (55%). Systolic function, as assessed by FS, was normal in all patients. NTG induced a significant acceleration of the LVOT velocities in all patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Systolic and diastolic arterial blood pressures (SBP, DBP) were measured in 181 consecutive patients (pts) by non-invasive method (oscillometric recorder SpaceLabs 90202). Hospitalised pts (N = 54) and ambulatory pts (N = 127) did not differ significantly in 24 hrs mean SBP, diurnal SBP, DBP nor heart rate (HR): respectively 132.9 vs 136.1 137.6 vs 138.2 86.2 vs 84.4 mmHg 79.6 vs 77.1 bpm. The circadian variation of HR was identical in the 2 groups. During night (0-6 hr AM) pressures decreased significantly less in hospitalised pts than in outpatients: respectively SBP - 6.4 vs - 17.9 p. cent DBP - 5.7 vs - 17 p. cent SBP day/SBP night ratio 1.06 vs 1.17 (p less than 0.001). This "equalization" was observed since the first day of hospitalisation, even if pts were not restricted to bed (pts in intensive care unit were excluded). It did not depend on age, sex, mean SBP nor antihypertensive treatments. Heart work, as evaluated by HR.SBP product, did not differ significantly during the day in the 2 groups. In hospitalised pts it decreased twice less and remains at a significantly higher level than in outpatients: respectively - 166 vs - 300 906 vs 792 cmHg/min (p less than 0.001). The standard deviation of SBP was significantly correlated with the SBP day/SBP night ratio (r = 0.64 p less than 0.001). The chronology of the circadian variations of HR and SBP are identical, but their amplitude differed in hospitalised pts suggesting that the regulatory mechanisms of HR and SBP are different.
We report the first case of aortic and mitral Haemophilus paraphrophilus endocarditis complicated by abscess of the aortic annulus in a 30-year old man with post-rheumatic mitral regurgitation. We recall the peculiar clinical features and course of this bacterial endocarditis of uncommon origin. We insist, in particular, on the occurrence of cerebral embolism and on the two-dimensional echocardiographic diagnosis of an aortic annulus abscess confirmed at surgery. Cure was obtained by aortic and mitral valve replacement and by the prolonged antibiotic therapy made necessary by the presence of cerebral lesions. After 3 months, there were no neurological sequelae, but doppler-echocardiography showed a persistent washed out pouch the reports of which with the surrounding structures were determined by transoesophageal echocardiography: moderate aortic regurgitation was detected at that level.
The object of this study was to determine the electrophysiological effects of 3-hydroxy-dihydroquinidine (3-OH-HQ) in man. The electrophysiological parameters were measured in 12 patients before and after intravenous infusion of 5 mg/kg of 3-OH-HQ in 15 minutes. The mean plasma concentrations obtained varied from 2.4 +/- 1.1 mg/l at the 20th minute to 0.9 +/- 0.3 mg/l at the 60th minute. In these concentrations, 3-OH-HQ did not cause hypotension or affect the heart rate and nodal conduction. It did, however, prolong infra-hisian and intraventricular conduction and ventricular repolarisation from the 20th to the 60th minute after starting the infusion. The peak effect was observed at the 20th minute (+19 +/- 3.4 ms; +14.6 +/- 3.5 ms; and +44.5 +/- 6.6 ms, respectively). The 3-OH-HQ increased the effective atrial and ventricular refractory periods at the 30th minute (+21.8 +/- 5.5 ms and +22.3 +/- 7 ms, respectively). However, the ventricular effect only was discernable at the 60th minute. These effects are quantitatively comparable to those of quinidine. Extrapolation of these results to the effects of chronic oral treatment should be reserved as the therapeutic zone of this new molecule has not yet been determined.
A doppler-echocardiographuc study of left ventricular hypertrophy and systolic functions was performed in 99 professional cyclists and 26 age, body surface and blood pressure-matched controls. The following T-mode echocardiographic parameters were determined: wall thickness and cavitary diameter, left ventricular mass (LVM), fibre shortening fraction (FSF) and ejection fraction (EF). The following doppler parameters were measured at the annulus (a) and tip (p) of the mitral valve leaflets: protodiastolic velocity peak (E), velocity peak during atrial systole (A) and A/E ratio. Compared with controls, the cyclists showed a significant increase of LVM (305 +/- 53 vs 174 +/- 41 g, p less than 0.0001) and of the h/R ratio of mean wall thickness (h) to cavitary radius (R) (0.40 +/- 0.04 vs 0.35 +/- 0.06, p less than 0.001). There was no significant difference between the two groups as regards FSF, EF and protodiastolic filling peak (E). In contrast, subjects in the cyclist group showed a significant increase of Ap (0.39 +/- 0.07 vs 0.47 +/- 0.09, p less than 0.001), Aa (0.36 +/- 0.07 vs 0.41 +/- 0.08, p less than 0.01) and A/Ep (0.54 +/- 0.12 vs 0.62 vs 0.62 +/- 0.11, p less than 0.0001). It is concluded that professional cyclists have an increase in size of their left ventricle and that repercussions of this enlargement on ventricular filling only appear during the atrial systole and are related to a slower heart rate.
Explore the source record for details and available documents.
Transoesophageal pacing is mainly used for treatment of supraventricular tachycardias and assessment of refractory periods of accessory pathways. It has been proposed for the study of sinus node function and A-V nodal conduction. The aim of this study was to know if transoesophageal pacing could modify the vago-sympathetic tone, therefore the results of the tests, knowing it can be discomfortable and that endodigestive procedures can induce vagal responses. Furthermore, the stimulation is elicited near the left atrium, and not in the right atrium as during endocavitary tests. We have compared in 20 patients (age 68 +/- 12) the results obtained by both endocavitary and transoesophageal pacing (tension 21.2 +/- 4.5 V, duration 16 msec, interelectrode spacing 30 mm). We measured sino-atrial conduction time (SACT), sinus node recovery time (SNRT), Wenckebach's point and nodal refractory periods. After introduction of the oesophageal lead we observed a significant (p less than 0.01) but slight and transitory tachycardia. The results of A-V nodal conduction parameters were not significantly different and were significantly correlated (r = 0.94 for Wenckebach's point and effective refractory period). For the sinus node function, there was no significant difference between the parameters if the oesophago-atrial delay (mean 104.4 +/- 25.9 msec) is taken into account. The correlation is poor for sino-atrial conduction time (corrected SACT, r = 0.55), tighter for sinus node recovery time (maximal corrected SNRT, r = 0.92).(ABSTRACT TRUNCATED AT 250 WORDS)
Sinoatrial conduction times, estimated by premature atrial stimulation, were compared with direct measurement of the sinoatrial conduction time in 15 isolated rabbit sinus node preparations before and after intrasinusal pacemaker shifts induced by cooling. Transmembrane potentials and surface electrograms were recorded from the sinus node and crista terminalis. Extracellular sinus node activity was recorded in five preparations. Mapping was performed at 38 degrees C and 35 degrees C to determine the site of the dominant pacemaker. The sinus cycle was significantly longer at 35 degrees C (319.4 ms vs 258.1 ms). Intracellular measured conduction time was significantly shorter (63.8 ms vs 70.4 ms) because of caudal shift of the dominant pacemaker. Estimated sinoatrial conduction time was significantly longer (110.3 ms vs 85.4 ms) owing to the depression of automaticity by the extrastimulus. Extracellular measured conduction time did not differ significantly from intracellular measured conduction time. These results suggest that intrasinusal pacemaker shift may explain inaccuracies in indirect estimations of sinoatrial conduction time by atrial pacing techniques. Extracellular recordings appear to be a better method of evaluating sinoatrial conduction times.
Ambulatory 24 hour electrocardiography by the Holter method was carried out in 134 normal subjects (59 men, 75 women, mean age: 42.5 +/- 14 years). The average heart rate over 24 hours was 75 +/- 9 bpm, 82 +/- 10 bpm during the daytime and 64 +/- 8 bpm at night. Maximal and minimal momentary variations (over 5 minutes) were small during the night (+23% and -7%) and greater during the daytime (+47% and -16%). The heart rate slowed progressively over a two hour period before going to bed an increased progressively over a three hour period, reaching a peak and then slightly falling before getting up. The average heart rates of women were faster than in men (+5 bpm). The average heart rate fell with age from 30 years onwards (-0.4 bpm per year). Tobacco consumption did not seem to affect the heart rate. Supraventricular extrasystoles were observed in 68% of subjects during the day, and in 50% during the night; ventricular extrasystoles occurred in 42% of subjects by day and in 23% by night. Only 22% of subjects had no extrasystolic activity. Tobacco consumption and sex were unrelated to the incidence and frequency of extrasystoles. On the other hand, the incidence and frequency of extrasystoles were very significantly related to age.
The ejection fraction and fractional shortening are parameters of left ventricular function dependent on the conditions of load. They are not perfect indices of myocardial contractility. The study of the relationships between stress and diameter and fractional shortening and stress in end-systole provides a better means of assessing the contractile state of the myocardium. The relationships between end-systolic stress-diameter and end-systolic stress-fractional shortening were studied non-invasively in 10 normal subjects (Group I) and 7 patients with severe dilated cardiomyopathy (Group II). End-systolic longitudinal stress of the left ventricle was calculated from Grossman's formula by coupling automatic measurement of blood pressure (cuff method) with simultaneous M mode recordings guided by 2D echocardiography. The line of regression of end-systolic stress-end-systolic diameter was determined in all cases from a series of 14 points obtained after sublingual administration of 10 mg of isosorbide dinitrate. The line of regression of fractional shortening-end-systolic stress was established in both groups by using the values observed under basal conditions and at the peak of action of the isosorbide dinitrate. The following results obtained: Under basal conditions, patients in Group II had greater end-diastolic diameters (69 +/- 8 vs 49 +/- 4 cm, p less than 0.01), greater end-systolic diameters (61 +/- 8 vs 33 +/- 4 mm, p less than 0.001) and higher end-systolic stress (140 +/- 54 vs 67 +/- 13 10(3) dyn/cm2, p less than 0.001). Fractional shortening was lower in Group II than in Group I (12 +/- 5 vs 33 +/- 5%, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
The effects of bepridil on sinoatrial conduction were studied by perfusing 15 isolate rabbit right atrial preparations. In a preliminary series an increase in cycle length was observed with a dose-dependent effect with concentrations of between 5 X 10(-7) M and 1 X 10(-5) M. At the latter dose, sinoatrial block was observed. Bepridil was therefore used in a series of 10 preparations to induce sinoatrial block (SAB). After 10 minutes perfusion the cycle length increased significantly (14.3%, p less than 0.02). In 4 preparations SAB occurred 18.7 +/- 2.5 minutes after the onset of the perfusion. Sinoatrial block did not occur in 6 cases and in 4 cases an intrasinus shift of the dominant pacemaker was observed. The types of SAB observed were varied and their mechanisms were complex. Different types of SAB occurred in the same preparation. The different types of block recorded were: Blumberger type I SAB, anterograde 2/1 SAB, intrasinus 2/1 block, retrograde 2/1 and advanced block, complete atrio-sinusal dissociation.