Programmed Chest-Wall Stimulation to Evaluate the Progress of A-V Block After Pacemaker Insertion in Patients with Trifascicular Disease

Twenty six patients (aged 46-80, mean age 64) with bifascicular block in the presence of prolonged H-V interval (trifascicular block), were followed for an average of 31 months after inserting an R-wave inhibited pacemaker (PM) because of syncope and/or dizzy attacks. The underlying rhythm was evaluated at 4-6-month intervals by three different techniques: 1) 12-lead ECG when intrinsic patient rate was faster than PM rate; 2) abrupt PM inhibition (APMI) by the rapid chest-wall stimulation technique, and 3) progressive PM inhibition (PPMI) using a programmed chest-wall stimulation technique capable of decreasing the PM rate gradually to 30 beats/min before complete PM inhibition. In addition, the PPMI allowed the underlying rhythm to be induced and sustained and properly evaluated without any discomfort to the patient. Following PM insertion, 4 patients (15%) developed complete heart block after a mean follow-up of 43 months, and one patient (4%) developed 2nd degree 2:1 A-V block (VX) after 83 months. The P-R interval increased in 5 patients (19%) and decreased in 2 (8%). No change of A-V conduction was found in 9 patients (34%). Three patients developed low atrial rhythm, atrial flutter and atrial fibrillation, respectively (12%). After PM insertion 2 patients still complained of dizziness. None reported syncope. Two patients died during follow-up, both of congestive heart failure (8%). By detection of intrinsic rhythm it was recognized that a long symptomatic paroxysmal phase may precede the development of chronic complete A-V block. Therefore, the insertion of a permanent PM is recommended in patients with unexplained neurologic symptoms and trifascicular disease, without waiting for documented episodes of complete A-V block.     

Neuromuscular Involvement in Glycogen Storage Disease Type III

ABSTRACT. Sixteen patients with glycogen storage disease type III (GSD III) aged 3 to 22 years underwent a detailed neuromuscular evaluation. A minimal impairment of skeletal muscle function was presented in eight patients, slight impairment in four and severe impairment in one patient. Serum creatinine phosphokinase (CPK) was elevated in all patients studied. In the nine patients, in whom electromyography (EMG) was performed; six exhibited a myopathic pattern while a "mixed" (neurogenic-myopathic) pattern was present in three. Muscle biopsies performed in 12 patients, revealed in all cases amylo-1,6,-glucosidase deficiency and biochemical as well as morphological evidence of glycogen accumulation. Two brothers suffered from late onset myopathy, which in the older sibling was associated with clinical, EMG and EM findings of a peripheral neuropathy. Fifteen patients had either electrocardiographic and or echographic evidence of cardiomyopathy. Observations based on this patient material suggest a widespread myopathy in GSD III patients with heterogeneous expression, while peripheral nerve involvement is rarely encountered.