Roger P. Javier

Significance of the Sinus-Node Recovery Time

The phenomenon of postpacing depression of cardiac pacemakers was utilized to evaluate the sinus-node function in 56 patients by analyzing the sinus-node recovery time (SRT), that is, the interval between the last paced P wave and the following sinus P wave. Corrected SRT (CSRT) is defined as the recovery interval in excess of the sinus cycle (SRT — sinus cycle length). The SRT was measured following sinus-node suppression by (1) isolated premature beats (PABs) and (2) atrial pacing (AP) at rates of 100 to 140/min for periods of 2 to 5 min at each level. Twenty-eight patients had normal heart rates (group A), and 28 patients had sinus bradycardia (SB; group B). Ten of the 28 patients with SB were restudied after receiving atropine (2 mg intravenously). The CSRT with PABs was similar in both group A and group B patients and remained essentially unchanged after atropine despite a decrease in sinus cycle length. The phenomenon of interpolated PABs was demonstrated in seven of the 56 patients. In 27 of the 28 patients with normal heart rates (group A), the CSRT with AP ranged from 110 to 525 msec and was essentially independent of the rate and duration of AP. In the remaining one patient of group A, despite a normal heart rate, the CSRT was prolonged (1810 msec) and directly dependent on the rate and duration of AP. In 12 of the 28 patients with SB, the CSRT was comparable to that in group A (≦525 msec). In the remaining 16 patients with SB (group B), the CSRT ranged from 560 to 3740 msec and was usually directly proportional to the rate and duration of AP. After atropine in most of the patients with a prolonged CSRT, the CSRT remained abnormal whereas in others junctional escape beats appeared first, followed eventually by normal sinus rhythm. In a single patient with SB and an abnormal CSRT, restudy 7½ months later again showed a prolonged CSRT indicating the reproducibility of the measurement. The CSRT with AP provides a potentially useful clinical means of assessing the sinus-node function and thereby aids in the diagnosis of the “sick sinus syndrome.’ It is stressed that AP was found to be more reliable than PABs in eliciting an abnormal response. Furthermore, a normal sinus (atrial) rate does not necessarily provide assurance of a normal sinus-node response to AP, that is, normal sinus-node function.

Myocardial dysfunction associated with valvular heart disease

Abstract Seventy-one patients undergoing valve replacement surgery were studied before and after operation to determine change of clinical condition and ventricular contractility. Preoperatively, all patients had functional class III or IV disease (New York Heart Association classification) and 55 percent had myocardial dysfunction. Post-operatively, the condition of 86 percent of patients improved clinically by at least 1 functional class, but 56 percent of patients had myocardial dysfunction. Cardiac index and left ventricular end-diastolic pressures were closely related to changes in angiographically determined myocardial contractility. Neither patient age, sex, duration of cardiopulmonary bypass, residual uncorrected valve disease nor coronary artery disease alone determined the degree of impairment in left ventricular contractility. A high incidence of myocardial dysfunction was found pre- and postoperatively in this study. In 16 patients with pure mitral stenosis, 6 (38 percent) had left ventricular dysfunction preoperatively, demonstrating intrinsic myocardial disease, possibly chronic rheumatic myocarditis. The demonstration of postoperative myocardial contractile abnormalities in previously normal patients suggests an intraoperative cause, perhaps related to cardiopulmonary bypass. Postoperative dysfunction may (1) exist preoperatively and remain unchanged, (2) occur intraoperatively, or (3) exist in a latent form preoperatively but be aggravated by the stress of surgery. Without both pre- and postoperative microscopic examination of the myocardium in the same patient, it is impossible to determine which process is primary.

Conversion of Supraventricular Tachyeardias with Rapid Atrial Stimulation

Rapid atrial stimulation (RAS) is a technic useful for converting the rapid ventricular response of atrial tachycardia, atrial flutter, or junctional tachycardia to a slower ventricular rate with normal sinus rhythm or atrial fibrillation. It is particularly useful when alternate methods such as DC cardioversion, carotid sinus massage, and drug therapy are either ineffective or undesirable. It is safe in patients with digitalis intoxication, does not require general anesthesia, documents atrial rhythm, and can be used repetitively without cumulative effects.RAS was performed 129 times in 87 patients (45 males; 42 females) whose ages ranged from 33 to 90 years (mean 67 years). There were no major complications. Overall, including both initial and repeat attempts, RAS successfully converted supraventricular tachycardia in 71% of cases and failed in 29%.

Progression of coronary artery disease: Cinearteriographic and clinical observations in medically and surgically treated patients

Abstract The evolutionary pattern of occlusive coronary artery disease was studied by comparing coronary cinearteriographic findings in repeated catheterizations of 85 patients. Fifty-six percent of 16 medically treated patients with coronary artery disease were found to have progression of occlusive coronary artery disease in the repeated study. Patients who had progressive coronary artery disease were similar to those with nonprogressive disease in age and in duration and severity of disease. A history of hypercholesterolemia seemed to be more frequent among patients with progressive than in those with nonprogressive coronary artery disease. Other risk factors of coronary artery disease were found to be similarly frequent among patients with progressive and nonprogressive disease. Progression of occlusive coronary artery disease was associated with a greater deterioration of cardiac function. Cardiac index decreased significantly in patients with progressive disease, and did not change very much in patients with nonprogressive disease. Among the patients with progressive disease, two had a myocardial infarction between catheterizations, whereas none of those with nonprogressive disease had infarction. Electrocardiographic findings were similar in both groups of patients, except for new infarction changes in the patients with progressive disease who sustained an infarct. Seventeen percent of 65 patients who underwent aortocoronary saphenous vein graft bypass surgery were found in the second study (average interval 10.1 months) to have proximal occlusion of a distally grafted vessel with a patent graft. Progression of disease in nongrafted coronary arteries was found in 6 percent of the surgically treated group. Of four patients who had internal mammary artery implantation, two had progression of coronary disease in a repeat study. Conclusions regarding the evolution and progression of coronary artery disease should be drawn only from medically treated patients, since coronary artery surgery may alter the natural course of this disease. Medically treated patients who are reconsidered for surgical treatment should have a repeat catheterization to detect any change in distribution of occlusive coronary artery disease and in cardiac function.

Cardiovascular dynamics during coronary sinus, right atrial, and right ventricular pacing

Abstract Permanent pervenous right atrial pacing has not been widely used to date. The coronary sinus may provide a site from where reliable permanent pacing can be performed so as to preserve atrial contribution in patients with intact A-V conduction who require pacing, as in sinus bradycardia, sinus arrest, and recurrent tachyarrhythmias. To test this hypothesis, 15 individuals, 37 to 70 years old (average 56.6 years), with a variety of heart diseases, but with normal A-V conduction, were studied. After control cardiac index had been obtained, coronary sinus, right atrial pacing, and right ventricular pacing were performed at two levels above the control sinus rate. Mean cardiac index was virtually identical for coronary sinus and right atrial pacing at the first level, 2.38 and 2.37 L./min./M. 2 , respectively, and at the second level, 2.45 and 2.42 L./min./M. 2 , respectively. During the first level of right ventricular pacing mean cardiac index was 1.87 L./min./M. 2 , 21.8 per cent lower than during coronary sinus pacing (p 2 , 23.3 per cent lower than during coronary sinus pacing (p The coronary sinus provides an area from which the heart can be paced with the hemodynamic advantages of atrial pacing if intact A-V conduction exists.

Partial anomalous pulmonary venous connection and drainage

Abstract The clinical, diagnostic and pathophysiologic features of 5 different types of partial anomalous pulmonary venous connection and drainage seen in 6 adult patients are presented. This distinct anatomic entity is perhaps more commonly prevalent than has been previously believed. It may be associated with other cardiac and pulmonary anomalies and also with acquired rheumatic valve disease.

Calcific aortic insufficiency—a review of 26 patients

Twenty-six patients, 8.3 per cent of all patients with aortic valve disease, and 10.7 per cent of all patients with any degree of aortic insufficiency detected in our catheterization laboratory, had pure calcific aortic insufficiency (no associated stenosis). Nineteen (73 per cent) males and seven (27 per cent) females ranged in age from 25 to 75 years of age (mean 51). Twenty-three per cent were younger than 40. Sixteen (62 per cent) had rheumatic heart disease, one had luetic aortic valve disease, one had congenital bicuspid valve, and eight (31 per cent) had aortic insufficiency of undetermined etiology. Twenty-three patients (89 per cent) had an aortic systolic ejection murmur, and seven (28 per cent) had an aortic ejection click. Aortic valve calcification was detected by plain chest films in only four patients (16 per cent), and by routine image intensification fluoroscopy (before catheterization) in fifteen patients (68 per cent). The reamining 32 per cent had the calcification of the aortic valve detected during catheterization. Aortic valve calcification was severe in nine patients (35 per cent), moderate in eleven patients (42 per cent), and minimal in six patients (22 per cent). Aortic insufficiency was severe in twenty patients (77 per cent), moderate in five patients (19 per cent), and minimal in one patient (4 per cent). Nineteen patients (77 per cent) had reduced left ventricular contractility. Sixteen patients (67 per cent) had low cardiac index. Eighteen patients had obstructive coronary artery disease. Aortic stenosis was misdiagnosed as the predominant lesion in fourteen patients (54 per cent)--prior to catheterization. This series demonstrates that all patients with calcified aortic valve disease and with ejection murmurs do not necessarily have aortic stenosis. Pure calcific aortic insufficiency is a distinct entity, more common than previously suspected.