Echocardiographic wall motion abnormalities and the signal averaged electrocardiogram in the acute phase of a first myocardial infarction

We studied the relationship between wall motion abnormalitiesdetermined by echocardiography and the signal-averaged electrocardiogramin 82 consecutive patients during the acute phase of a firstmyocardial infarction. An abnormal signal-averaged electrocardiogramwas defined as the presence of two of the following criteria:a QRS duration 114 ms, a root mean square voltage (RMS) ofthe last 40 ms 25 µV and an amplitude signal lower than40µV lasting 39 ms. The left ventricle was divided into13 segments and the contraction pattern divided into akinesiaalone (including dyskinesia) (group A), hypokinesia alone (groupB) and both hypokinesia and akinesia (group C). An abnormal signal-averaged electrocardiogram was found in 14/82patients (17%) and was correlated with the persistence of occlusionof the infarct-related vessel (32% vs 9%. P < 0.02). In patientswith a patent vessel, the incidence of an abnormal signal-averagedelectrocardiogram was 14% in group A, 9% in group B and 0% ingroup C (NS). In patients with an occluded vessel an abnormalsignal-averaged electrocardiogram was found in 10% of groupA patients, in 36% in group B patients and in 75% of group Cpatients (P = 0.05). Our study suggests that the presence of hypokinetic areas duringthe acute phase of a first myocardial infarction and an abnormalsignal-averaged electrocardiogram indicate an occluded infarct-relatedvessel.     

Regional Disparities of Endocardial Atrial Activation in Paroxysmal Atrial Fibrillation

Previous experimental data suggest that atrial activity is homogeneously distributed during paroxysmal atrial fibrillation (AFib). Little is known about this in human paroxysmal AFib. Methods : Twenty-five men and two women (mean age 49 ± 11 years; five with structural heart disease) with paroxysmal AFib for a mean 5 ± 6.2 years despite the use of a mean of 3.6 ± 1.7 antiarrhythmic drugs underwent atrial mapping. The right atrium was divided into four regions: posterior (intercaval), lateral, anterior, and septal. A 14-pole catheter was positioned to assess complex electrical activity defined as the duration of continuous electrical activity or electrograms with FF intervals < 100 ms for 60 seconds (expressed as percentage of time). In addition, the left atrium (divided into three regions: posterior, anterior, and septal) was explored in 12 patients with a multipolar catheter. Results : The complex electrical activity time between all the regions explored was significantly different. In the right atrium, the septa] (74%± 32%; P = 0.02) and the posterior (63%± 32%; P = 0.04) areas were significantly more disorganized than the lateral (22%± 23%) and anterior (21 %± 26%) regions. In the left atrium, complex electrical activity was predominant and widely distributed (posterior: 87%± 11%; septal: 65%± 27%) except in the appendage area (anterior region: 18%± 14%). Conclusions : Quantitative assessment of complex electrical activity in both atria in humans shows heterogeneous temporal and spatial distribution. This may have implications for guiding catheter ablation of AFib.     

Radiation Exposure During Radiofrequency Catheter Ablation for Atrial Fibrillation

MACLE, L., et al. : Radiation Exposure During Radiofrequency Catheter Ablation for Atrial Fibrillation. RF catheter ablation of paroxysmal atrial fibrillation (PAF) is associated with prolonged fluoroscopy. The procedural duration and fluoroscopic exposure to patients and medical staff were recorded and compared among 43 ablation procedures for PAF, 20 for common atrial flutter, and 16 for accessory pathways. Patient radiation exposure was measured by dosimeters placed over the xyphoid, while that of physicians and nurses was measured by dosimeters placed outside and inside the lead apron. The mean fluoroscopy time was   57 ± 30   minutes for PAF,   20 ± 10   minutes for common flutter, and   22 ± 21   minutes for accessory pathway ablation. The patient median radiation exposure was 1110μSv for PAF, compared with 500 μSv for common flutter and 560 μSv for accessory pathway ablation (P < 0.01). The median radiation exposure to physician and nurse inside the lead apron were, respectively, 2 μSv and 3 μSv for PAF, 1 μSv and 2 μSv for common flutter, and <0.5 μSv and 3 μSv for accessory pathway ablations. RF catheter ablation for PAF was associated with prolonged fluoroscopy times and a twofold higher radiation exposure to the patient and physician compared with other ablation procedures. Assuming 300 procedures/year, radiation exposure to the medical staff was below the upper recommended annual dose limit. (PACE 2003; 26[Pt. II]:288–291)     

Cost Analysis of Catheter Ablation for Paroxysmal Atrial Fibrillation

WEERASOORIYA, R., et al. : Cost Analysis of Catheter Ablation for Paroxysmal Atrial Fibrillation . RF ablation for paroxysmal atrial fibrillation (PAF) is a curative treatment, which when successful, eliminates the need to take antiarrhythmic drugs, be anticoagulated, and have recurrent physician visits or hospital admissions. The authors performed a retrospective cost comparison of RF ablation versus drug therapy for PAF. The study population consisted of 118 consecutive patients with symptomatic, drug refractory PAF who underwent   1.52 ± 0.71   RF ablation procedures (range 1–4) for PAF. During a follow-up of 32 ± 15 weeks, 85 (72%) patients remained free of clinical recurrence in absence of antiarrhythmic drugs. The cost of RF ablation was calculated in the year 2001 euros on the basis of resource use. The mean cost of pharmacologic treatment prior to ablation was 1,590 euros/patient per year. The initial cost of RF ablation for PAF was 4,715 euros, then 445 euros/year. After 5 years, the cost of RF ablation was below that of ongoing medical management, and continued to diverge thereafter. RF catheter ablation may be a cost-effective alternative to long-term drug therapy in patients with symptomatic, drug refractory PAF. (PACE 2003; 26[Pt. II]:292–294)     

Studies on Agranulocytosis. II. The Effect of Chlorpromazine upon the Influx of S35 L-Cystine and L-Methionine into Human Leukocytes

1. When whole blood was incubated in vitro with S-35 L-cystine and L-methionine, the blood cells became radioactive.

2. Preincubation of whole blood from normals and from patients susceptibleto agranulocytosis with chlorpromazine showed no effect upon uptake of S-35L-cystine and L-methionine by leukocytes.

3. The in vivo administration of S-35 L-cystine was followed by the appearance of radioactive leukocytes. Peak radioactivity occurred in leukocytes in 5to 12 days.

4. Pretreatment of test subjects with large doses of chlorpromazine did notblock the uptake of S-35 L-cystine by leukocytes in vivo. Leukocytes of womenshowed an increase in the incorporation of S-35 L-cystine, in vivo. Studiesperformed in vivo on two persons during recovery from agranulocytosisshowed enhanced uptake of L-cystine in one and a normal uptake in the other.

Submitted on March 24, 1960 Accepted on July 13, 1960     

MALE PSEUDOHERMAPHRODITISM WITH HYPERTENSION DUE TO A 17α-HYDROXYLATION DEFICIENCY

A case of male pseudohermaphroditism aged 48 years with systemic hypertension and hypokalaemic alkalosis is described. Results of metabolic studies point to a 17alpha-hydroxylase deficiency demonstrated by low cortisol (0-56 mg/24 h), high corticosterone (270 mg/24 h) and 11-deoxycorticosterone (5 mg/24 h) secretion rates. Adrenocorticotrophin and gonadotrophin levels were markedly raised but plasma androstenedione (3 ng/dl), testosterone (17 ng/dl), oestrone (3 ng/dl) and oestradiol(1-8 ng/dl) were all low. Plasma aldosterone levels and secretion rates in urine were low and were surprisingly unaffected by dexamethasone therapy although low renin levels rose with a marked return of the erect posture effect. Therapeutic levels of dexamethasone were, however, followed by incipient renal failure.     

Long-Term Follow-Up After Right Atrial Radiofrequency Catheter Treatment of Paroxysmal Atrial Fibrillation

Catheter ablation of paroxysmal atrial fibrillation using long linear lesions in the right atrium is still under investigation, and its long-term follow-up is unknown. Methods: Thirty-six men and nine women (aged 51 ± 12 years) with symptomatic daily episodes of AF for 6 ± 5 years despite the use of 4.7 ± 1.5 antiarrhythmic drugs were studied between July 1994 and January 1996. Progressively longer ablation lines were performed in 3 groups of 15 consecutive patients each, using a 14-electrode catheter or a single-electrode dragging technique. Success was defined as atrial fibrillation elimination or recurrence for no longer than 6 hours over 3 months of observation. Patients who had fewer than 6 hours of atrial fibrillation per month were considered "improved." Medium- (11 ± 4 months) and long-term (26 ± 5 months) results were assessed clinically from a patient's diary and from Holter recordings. Results: After a follow-up of 11 months, 24 patients had a favorable result of the ablation procedure with or without additional antiarrhythmic drug therapy, representing 53% of the original cohort. After 26 ± 5 months of follow-up, these successful results were reduced to 17 patients (37%). Conclusions: After linear atrial ablation, a significant long-term attrition of arrhythmia-free patients was observed. This may be due to a combination of disease progression, incomplete linear block, and ineffective ablation of arrhythmogenic triggers.     

Synthesis of Thiazolotriazine Derivatives and Their Antinociceptive Effects in Mice

A series of 2-(4-arylpiperazin-1-yl-methyl)-4-methyl-1-oxo-5,6,8,8a-tetrahydro-thiazolo[3,4-d] [1,2,4]triazines was prepared and tested for antinociceptive activity. The compounds were prepared by the Mannich reaction from the corresponding 2-unsubstituted thiazolotriazines. When administered intraperitoneally most were found to have potent analgesic activity in the mouse during tests of phenylbenzoquinone-induced abdominal constriction; ED50 values (doses resulting in half the maximum effect) ranged from 10 to 87 mg kg^?1. Derivatives with a 3-chloro- or 4-fluorophenylpiperazinylmethyl side-chain in the 2-position of the bicyclic system were, when administered intraperitoneally at doses greater than 25 mg kg^?1, also effective in the hot-plate test without associated sedative effects. The compounds have a large therapeutic index; intraperitoneal LD50 values (doses which result in the death of half the animals) were > 700 mg kg^?1. Naloxone attenuated the analgesic activity of the 3-chloro derivative, suggesting the participation of μ-receptors in the antinociceptive effects of this drug. In addition, a non-opioid mechanism, probably related to enhancement of the release of 5-hydroxytryptamine and noradrenaline, or inhibition of the neuronal re-uptake of these compounds, has been evinced to explain the analgesic properties of the 3-chloro or 4-fluoro derivatives. These results provide evidence for the involvement of noradrenergic and 5-hydroxytryptaminergic pathways in the analgesic activity of 3 and 4. Because of their potential effectiveness, the 3-chloro- or 4-fluorophenylpiperazinylmethyl derivatives might be suitable for treatment of a wide variety of painful conditions and could be attractive reserve agents for patients dissatisfied with opioids.