Claude Sebag

Complete atrioventricular block following mediastinal irradiation: A report of six cases

Complete atrioventricular block (AVB) following radiotherapy has been reported rarely, usually after high dose mediastinal irradiation for Hodgkins disease or Jung or breast carcinoma. We report six new cases of episodic complete infranodal AVB, requiring permanent pacemaker implantation. The mean age was 48‐years old (ranging from 25–60) at the first Adams Stokes attack, mean delay was 12 years after irradiation (10–18), and mean radiation dose was 5.200 rads (4,000–6,500). All patients had abnormal interval electrocardiograms (right bundle branch block in two, left bundle branch block in three, alternating left and right bundle branch block in one). Electrocardiograms during the episode of AVB or Holter recordings were consistent with infranodal block in all patients; eleclrophysiological study performed in five patients confirmed infranodal AVB in four, and one was normal. Pericardial disease was constant, which included pericardial constriction in four patients. Two patients died after failure of pericardiectomy to improve congestive heart failure, due to epicardial, myocardial, and endocardial involvement. Noncardiac mediastinal lesions were present in four cases. Since this delayed complication may occur in patients of such age that the relation between the AVB and the chest irradiation is questionable, we propose the following etiologic criteria: high radiation dose (over 4,000 rads); delay of 10 years or more; abnormal interval tracings: pericardial involveinent; and associated cardiac or mediastinal radiation‐induced lesions.

Prophylactic pacemaker implantation in familial amyloid polyneuropathy.

BACKGROUND Familial amyloid polyneuropathy (FAP) is an autosomic dominant disease with a high rate of conduction disorders and increased risk of sudden death. Prophylactic cardiac pacing may be considered in asymptomatic patients with FAP. However, the potential benefits are unknown. OBJECTIVE To document conduction disorders in a large series of FAP and the incidence of high-degree atrioventricular (AV) block in patients with prophylactic pacemaker (PM). METHODS From January 1999 to January 2010, 262 patients with FAP were retrospectively evaluated. Prophylactic PM was implanted in patients with His-ventricular interval ≥ 70 ms, His-ventricular interval >55 ms associated with a fascicular block, a first-degree AV block, or a Wenckebach anterograde point ≤ 100 beats/min. The spontaneous AV conduction was then analyzed by temporarily inhibiting the PM. RESULTS As compared with patients with prophylactic PM (n = 100) and patients implanted given a class I/IIa indication (n = 18), the patients who did not require PM (n = 144) were younger and displayed less severe cardiac involvement. Follow-up after prophylactic PM implantation was analyzed in 95 of the 100 patients over 45 ± 35 months, and a high-degree AV block was documented in 24 of the 95 patients (25%). The risk of high-degree AV block was higher in patients with first-degree AV block or Wenckebach anterograde point ≤ 100 beats/min (hazard ratio 3.5; 95% confidence interval 1.2-10) while microvoltage on surface electrocardiogram reduced the risk (hazard ratio 0.2; 95% confidence interval 0.1-0.7). CONCLUSION In FAP with conduction disorders, prophylactic PM implantation prevented major cardiac events in 25% of the patients over a 45-month mean follow-up. It is suggested that prophylactic PM implantation prevented symptomatic bradycardia in these patients.

Initial and Long-Term Evaluation of Escape Rhythm After Radiofrequency Ablation of the AV Junction in 50 Patients

Between 1986 and 1994, 50 patients (mean age 63 ± 13 years), 25 of whom had organic heart disease and presenting with atrial arrhythmias refractory to 5.6 ± 1.6 antiarrhythmic drugs, underwent radiofrequency ablation (5 ± 3 pulses by procedure; duration of pulses 50.5 ± 32 s) of the proximal AV junction to create complete and permanent AV block. The escape rhythm was studied immediately after the procedure and during long‐term follow‐up. Immediately after the procedure, an escape rhythm was observed in 80% of the patients (junctional in 92%). Over a mean follow‐up of 36 ± 16 months in 47 patients (2 patients died before assessment of escape rhythm and 1 was lost to follow‐up), an escape rhythm was present in 39 patients (83%) and absent in the remaining 8 (17%). The only significant difference between the two groups was the initial presence of an escape rhythm (P = 0.008). However, three patients with an initial escape rhythm had none during long‐term follow‐up. The initial presence of an escape rhythm as a predictive factor of its presence during follow‐up had a sensitivity of 87%, specificity of 63%, positive predictive value of 92%, and negative predictive value of 50%. Thus, the absence of an escape rhythm during long‐term follow‐up causing pacemaker dependency was noted in 1 of 6 patients. This represents a limitation to this palliative treatment, which should be reserved for patients suffering from supraventricular tachycardias refractory to other treatments.

Circadian rhythm of blood pressure reflects the severity of cardiac impairment in familial amyloid polyneuropathy

BACKGROUND Cardiac amyloidosis due to familial amyloid polyneuropathy (FAP) includes restrictive cardiomyopathy, thickened cardiac walls, conduction disorders and cardiac denervation. Impaired blood pressure variability has been documented in FAP related to the Val30Met mutation. AIMS To document blood pressure variability in FAP patients with various mutation types and its relationship to the severity of cardiac involvement. METHODS Blood pressure variability was analysed in 49 consecutive FAP patients and was compared with a matched control population. Cardiac evaluation included echocardiography, right heart catheterization, electrophysiological study, Holter electrocardiogram and metaiodobenzylguanidine (MIBG) scintigraphy. RESULTS A non-dipping pattern was found in 80% of FAP patients and in 35% of control patients (P<0.0001); this was due to a significantly lower diurnal blood pressure in FAP patients (FAP group, 113 ± 21 mmHg; control group, 124 ± 8 mmHg; P<0.0001), whereas nocturnal blood pressures were similar. Among FAP patients, a non-dipping pattern was significantly associated with haemodynamic involvement, cardiac thickening or conduction disorders. These associations did not depend on the average blood pressure levels. Impaired blood pressure variability was more frequent and more pronounced in patients with multiple criteria for severe cardiac amyloidosis. CONCLUSION Low blood pressure variability is common in cardiac amyloidosis due to FAP. A non-dipping pattern was more frequently observed in FAP patients with haemodynamic impairment, cardiac thickening or conduction disorders. It is suggested that impairment of circadian rhythm of blood pressure reflects the severity of cardiac amyloidosis due to FAP.

Rupture of the stomach and the esophagus after attempted transcatheter ablation of an accessory pathway by direct current shock

Abstract We describe a patient who ruptured her stomach and esophagus after attempted fulguration of an accessory pathway.

Phase mapping of radionuclide gated biventriculograms in patients with sustained ventricular tachycardia or Wolff-Parkinson-White syndrome.

SummaryAccuracy of Fourier phase mapping of radionuclide gated biventriculograms in detecting the origin of abnormal ventricular activation was studied during ventricular tachycardia or preexcitation. Group I included six patients suffering from clinical recurrent VT; 3 gated blood pool studies were acquired for each patients with Wolff-Parkinson-White syndrome and recurrent paroxysmal tachycardia; 3 gated blood pool studies were acquired for each patient: during sinus rhythm, right atrial pacing and orthodromic reciprocating tachycardia. Each acquisition lasted 5 min, in 30‡–40‡ left anterior oblique projection.In Group I, the Fourier phase mapping was consistent with QRS morphology and axis during VT (5/6), except in one patient with LV aneurysm and LBBB electrical pattern during VT. Origin of VT on phase mapping was located in the right ventricle (n=2) or in left ventricle (n=4), at the border of wall motion abnormalities each time they existed (5/6).In Group II, the phase advance correlated with the location of the accessory pathway determined by ECG and endocardial mapping (n=6) and per-operative epicardial mapping (n=1). Discrimination between anterior and posterior localisation of paraseptal pathways and location of intermittent preexcitation was not possible.We conclude that Fourier phase mapping is an accurate method for locating the origin of VT and determining its etiology. It can help locate the site of ventricular preexcitation in patients with only one accessory pathway; its accuracy in locating multiple accessory pathways remains unknown.

Regional phase mapping of radionuclide gated biventriculograms in patients with sustained ventricular tachycardia

Knowledge of origin site of sustained ventricular tachycardia (VT), and its spatial relationship with regional myocardial abnormalities, are often useful to predict pathophysiology of VT, and to guide surgical or electrical therapy. It usually requires a cardiac catheterization for angiography and/or endocardial mapping. Functional images of gated equilibrium radioventriculography (GERV) can provide non invasive data on ventricular activation. The phase pattern of the first harmonic of Fourier analysis may represent the sequence of ventricular contraction, which follows the sequence of intra-ventricular conduction. It has been used to study abnormalities of ventricular electromechanical activation as they are observed in bundle branch block [1–2] pacemaker rhythms [3–8], Wolff-Parkinson-White syndrome [9–14] and VT [15–18]. We studied the ability of Fourier analysis to locate the onset of ventricular activation during VT, and to determine the etiology of VT in 6 patients.