Motility Studies in Fifty Patients with Achalasia of the Esophagus

Esophageal motility tests with constantly perfused polyethylene catheters were done in 50 patients with achalasia of the esophagus using 30 asymptomatic adults as control. The mean gastroesophageal sphincter pressure was 19.0 ± 1.3 mm. Hg. (mean ± SE) which was significantly higher than the control group (P < 0.001). The intraesophageal resting pressure was significantly higher than the mean fundic pressure and no correlation among resting gastroesophageal sphincter pressure and resting intraesophageal pressure was found. An incomplete relaxation of the sphincter after swallowing was found in 45 patients with achalasia as opposed to complete sphincter relaxation in normals.     

The role of collateral blood supply in ventricular tachycardia after myocardial infarcation

The hypothesis that collateral or anterograde blood supply toan infarcted area maintains blood supply to cells responsiblefor ventricular tachycardia after myocardial infarction wasstudied in six patients. All patients had suffered a myocardialinfarction and developed spontaneous episodes of sustained monomorphicventricular tachycardia. The arrhythmia was paroxysmal in threepatients and incessant in the other three. During ventriculartachycardia iced isotonic saline (10 ml in approximately 4 s)was injected first in the coronary artery ostia and thereaftersuperselectively in the coronary artery providing collateralor anterograde blood supply to the infarcted area. A 2.5-F catheterwas used superselectively to catheterize coronary arteries ofapproximately 2–3 mm lumen for that purpose. Three patientshad anterograde blood supply to the infarcted area through areperfused infarct-related vessel. Two patients had only collateralretrograde blood supply to the infarcted region. One patienthad both anterograde and retrograde collateral blood supplyto the area of infarction. Ventricular tachycardia was not terminatedin any patient during non-selective injection of iced salinein the coronary ostia. In five of the six patients ventriculartachycardia was terminated by the super-selective administrationof iced saline. The morphology of ventricular tachycardia waschanged many times, but did not terminate, in the remainingpatient. Termination or change in morphology was achieved duringadministration of iced saline through collateral vessels intwo patients through the coronary artery supplying anterogradeflow in three patients and both through collaterals and anterogradeflow in the remaining patient. It is concluded that collaterolvessels or anterograde flow through the infarct-related vesselmaintain the viability of electrically normal, but electricallybadly coupled, cells responsible for ventricular tachycardiaafter myocardial infarction.     

Coronary Artery Bypass Grafting and Defibrillator Implantation in Patients with Ventricular Tachyarrhythmias and Ischemic Heart Disease

In patients with sustained ventricular tachyarrhythmias and myocardial ischemia due to multivessel coronary artery disease, it remains unclear whether revascularization is enough to control the arrhythmias or whether additional implantation of a defibrillator is indicated. We therefore reviewed our clinical strategy of performing both bypass surgery and implantation of a defibrillator in patients with syncopal ventricular tachycardia or fibrillation and significant multivessel coronary artery disease. We retrospectively reviewed the outcome of 18 patients with malignant ventricular tachyarrhythmias, significant multivessel coronary artery disease, and signs of myocardial ischemia who underwent both bypass surgery and defibrillator implantation. Data on these patients were compared to data from 232 other defibrillator patients with respect to baseline clinical variables, cardiac events, and mortality during follow-up. Except for underlying pathology, no other important differences in baseline characteristics were noted between the study patients and the other defibrillator patients. The cumulative occurrence of shocks during follow-up was comparable in both groups (66% vs 67%). The cumulative survival from all-cause mortality was 94% in the study patients and 78% in the others (P = NS). Pre- and postoperative electrophysiological testing was not useful to predict arrhythmia recurrences. In this population of patients with ventricular tachyarrhythmias and ischemia due to multivessel coronary artery disease, bypass surgery alone would not have prevented recurrences of arrhythmias. An excellent survival and a high incidence of shocks after both bypass surgery and defibrillator implantation were observed.     

Atrioventricular nodal tachycardia with and without discontinuous anterograde atrioventricular nodal conduction curves: a reappraisal of the dual pathway concept

To illustrate the complexity of the electrophysiological behaviourof the human alrioventricular (A–V) node, two patientssuffering from A–V nodal tachycardia are described. Duringtachycardia an A–V nodal slow pathway was used for anterogradeconduction, and an A–V nodal fast pathway for retrogradeconduction. Patient 1 showed smooth A–V nodal conductioncurves in both the anterograde and the retrograde direction.Tachycardia could only be initiated by ventricular prematurebeats. No critical delay in ventriculo-atrial conduction timewas required for initiation of tachycardia. Patient 2 showedsmooth A–V nodal conduction curves at the lowest rateof pacing during atrial and ventricular stimulation. The curvesbecame discontinuous in both directions when the basic drivencyclelength was decreased. Tachycardia could only be initiated byatrial premature beats. Ventricular premature beats inducednon-sustained A–V nodal reentry that used an A–Vnodal fast pathway for anterograde conduction, and an A–Vnodal slow pathway for retrograde conduction. Accepting dualpathways in the anterograde and retrograde directions in theA–V node, means that depending upon their electrophysiologicalproperties a large number of combinations of anterograde andretrograde conduction are possible. When more than two A–Vnodal pathways are present, the number of possible combinationswill increase markedly. These considerations are of help inunderstanding electrophysiological findings in patients withA–V nodal tachycardia. They are also useful to explainthe importance of autonomic tone and the results of drug administrationin these patients.