ABSTRACT
Two patients were investigated for paroxysmal regular tachycardia with left bundle branch block centrifugation. A right-sided nodo-ventricular accessory pathway was demonstrated in both cases at electrophysiological investigation with His bundle recording and atrial and ventricular programd pacing techniques. However, the function of this pathway was different in the two cases. In the first case, there were no signs of an accessory pathway on the surface ECG in sinus rhythm but it could be unmasked by simple right atrial pacing at the same rhythm (widening of the QRS and shortening of HV from 40 to 25 ms). The tachycardias could be only initiated by ventricular extrastimulus. They showed major pre-excitation with left sided delay and a 1/1 atrio-ventricular response. There was no His potential before the ventriculogramme which retained the same configuration throughout the attack. The investigations also suggested the presence of a dual nodal pathway with the accessory pathway connected to the slow pathway. In the second case, the presence of an accessory pathway could be suspected from the appearance of the QRS complex in sinus rhythms. Tachycardia was initiated by an atrial extrastimulus with initially a first complex showing slightly more marked pre-excitation and a distinct His potential before the QRS but with a shorter HV interval than in sinus rhythm. Then the reciprocating tachycardia had appearances of major pre-excitation, left-sided delay and a 1/1 atrio-ventricular response. However, in contrast to the first case, all ventricular complexes were preceded by a His potential and the degree of pre-excitation was variable with a HV interval ranging from 0 to 15 ms. These two cases merit attention because of: --their points in common: nodal duality and an accessory pathway which was not atrio-ventricular (decremental conduction) but nodo-right ventricular, conducting well in the anterograde direction but more or less masked in sinus rhythm; the presence of the accessory pathway was clearly visible during reciprocating tachycardia; --the differences: in the first case the nodo-ventricular pathway formed part of the circuit of the reciprocating tachycardia which was antidromic: descending limb, the slow nodal pathway and then the accessory nodo-ventricular pathway; ascending limb, the His bundle and then the rapid nodal pathway. In the second case, the reciprocating tachycardia was entirely intranodal, the accessory pathway not being involved in the circuit but connected to it in parallel with the normal Hisian pathway.
Subject(s)
Atrioventricular Node/physiopathology , Heart Conduction System/physiopathology , Tachycardia, Paroxysmal/physiopathology , Adult , Bundle of His/physiopathology , Bundle-Branch Block/complications , Bundle-Branch Block/physiopathology , Electrocardiography , Electrophysiology , Female , Humans , Middle Aged , Sinoatrial Node/physiology , Tachycardia, Paroxysmal/complicationsABSTRACT
The case of a patient with Von Recklinghausen's disease with multiple localisations, cardiac, aortic, pulmonary and renal artery is reported. Neurofibromatosis was confirmed by the presence of a "royal" tumour on the left elbow and of many "café au lait" spots of over 15 mm diameter. There was no craniofacial dysmorphism or intellectual impairment. The karyotype was normal. The cardiovascular lesions comprised: - stenosis of the left renal artery resulting in renovascular hypertension. This was due to pure intimal hyperplasia; - supravalvular aortic stenosis with hypoplasia of the ascending aorta. There was no craniofacial dysmorphism or intellectual impairment. The karyotype was normal. The cardiovascular lesions comprised: - stenosis of the left renal artery resulting in renovascular hypertension. This was due to pure intimal hyperplasia; - supravalvular aortic stenosis with hypoplasia of the ascending aorta. There was no craniofacial dysmorphism or intellectual impairment. The karyotype was normal. The cardiovascular lesions comprised: - stenosis of the left renal artery resulting in renovascular hypertension. This was due to pure intimal hyperplasia; - supravalvular aortic stenosis with hypoplasia of the ascending aorta, severe aortic regurgitation with dilatation of the aortic ring without rheumatic valvular thickening; - supra valvular pulmonary stenosis which was atypical in site, extension and in the absence of post stenotic dilatation. The pressure gradient was mild (22 mm Hg). There was a striking similarity between the pulmonary and aortic lesions. This new syndrome may be classified amongst the genetic cardiocutaneous syndromes such as the Gorlin or "leopard" syndrome, Watson's syndrome and Noonan's syndrome. Unusual features are the absence of craniofacial abnormalities, normal intelligence, and the left-sided dominance aggravated by hypertension due to curable intimal stenosis of the renal artery.