Subject(s)
Heart Rate , Myocardial Infarction/physiopathology , Adolescent , Aged , Arrhythmias, Cardiac/etiology , Blood Circulation Time , Blood Pressure , Blood Volume , Carbon Dioxide/blood , Cardiac Catheterization , Cardiac Output , Cardiac Volume , Electrocardiography , Heart Atria , Heart Failure/etiology , Humans , Hydrogen-Ion Concentration , Male , Middle Aged , Myocardial Infarction/complications , Oxygen/blood , Pacemaker, Artificial , Pulmonary Artery , Radioisotope Dilution Technique , Vascular ResistanceSubject(s)
Angiocardiography , Coronary Circulation/drug effects , Diatrizoate/pharmacology , Blood Flow Velocity , Blood Pressure/drug effects , Coronary Disease/physiopathology , Diatrizoate/administration & dosage , Humans , Injections , Pulse/drug effects , Radioisotopes , Time Factors , Vascular Resistance/drug effects , XenonABSTRACT
Increasing the heart rate by a bedside atrial pacing technique was successfully utilized to treat serious cardiac arrhythmia or failure in 13 patients. Nine of these had ventricular arrhythmia refractory to drugs. Seven had evidence of sinus node depression or disease since their sinus pacemaker was below 70 beats per minute under decompensated conditions. In five, coronary artery disease was associated with the bradycardia and in two, digitalis toxicity was related to depression of the intrinsic pacemaker rate. Two patients in the coronary group required implantation of a permanent demand ventricular pacemaker. Hemodynamic studies were performed in seven patients. Only one patient had no increase in cardiac output with pacing rates above his resting rate. The other six patients showed an increase in cardiac output from 22 to 81% at paced rates between 70 and 125/minute. The duration of pacing ranged from one hour to 14 days and averaged five days.
