Robert G. Trout

Nitroglycerin to Unmask Reversible Asynergy Correlation with Post Coronary Bypass Ventriculography

The value of nitroglycerin in determining the potential reversibility of asynergy was examined in 35 patients with coronary heart disease. Ventriculograms performed at rest and after sublingual nitroglycerin were analyzed for (1) location of asynergy relative to distribution of the 3 major coronary arteries and (2) severity of asynergy. Of the 41 hypokinetic zones, 30(73%) improved following nitroglycerin. Of 28 akinetic zones, 16 (57%) improved (7 of the 16 segments becoming normal) following nitroglycerin. None of 7 dyskinetic zones showed change following nitroglycerin. Twelve patients were restudied following coronary bypass surgery. There was an excellent over-all correlation between the segments that responded to nitroglycerin and bypass surgery in those segments with open grafts. Eighteen segments which improved following nitroglycerin had patent postoperative grafts, and in 15 segments there was a corresponding improvement following bypass surgery. Two segments which were unresponsive to nitroglycerin preoperatively had patent postoperative bypass grafts. Neither segment improved despite graft patency. In summary, sublingual nitroglycerin is useful in unmasking residual contractile ability in asynergic zones. A positive response to nitroglycerin appears to be predictive of corresponding beneficial effect from a coronary bypass graft. The data strongly suggest that the use of nitroglycerin to determine residual contractile ability may be of considerable value in better defining the potential risks and benefits of coronary bypass surgery.

Reversible asynergy. Histopathologic and electrographic correlations in patients with coronary artery disease.

Histopathologic-electrographic studies of ventriculography depicted nitroglycerin responsive and unresponsive asynergic areas were performed in 25 patients. Of 29 areas, 12 improved with nitroglycerin, showing < 10% muscle loss. Seventeen unimproved zones demonstrated significant fibrosis. Epicardial electrograms showed R waves in eight of nine improved zones. Of 11 unimproved zones, eight had Q waves.Histopathologic-electrographic data from five responders showed < 10% muscle loss, of whom four had epicardial R waves. Six unresponsive areas had significant fibrosis, with a QS over four.Thus, nitroglycerin responsive asynergic areas are generally comprised of histologically intact myocardium and are associated with epicardial R waves.

One hundred neodymium-YAG laser ablations of obstructing tracheal neoplasms.

Forty patients with obstructing, nonresectable tracheal neoplasms underwent 100 ablations with the neodymium-yttrium-aluminum garnet (YAG) laser. The laser allows bloodless resection and vaporization of tumors. Unlike the carbon dioxide laser, the neodymium-YAG laser can be used with the flexible bronchoscope and has an excellent effect on coagulation. Thirty-four patients had primary lung malignancies (epidermoid in 24); 4 had metastatic malignancies; and 2 had benign lesions. Results have been excellent in 22, fair in 10, and poor in 8. No patient has died or had a deleterious result. Complications have occurred in only 1 of 89 ablations done with the flexible bronchoscope. We believe that the neodymium-YAG laser is effective in opening major tracheal or bronchial obstructions and offers substantial symptomatic improvement in patients who are short of breath. Although this treatment is only palliative, the results have been excellent in more than half of the patients.

Local characteristics of the normal and asynergic left ventricle in man.

The significance of ventricular asynergy in determining medical prognosis and surgical risk in patients with coronary artery disease and its delineation by ventriculography have been of increasing interest. To determine the underlying histopathologic and electrographic features of left ventricular asynergy, 39 patients undergoing open heart surgery were studied. Thirty-six histopathologic specimens were obtained in 31 patients (26 as transmural needle biopsies and 10 as aneurysm resections). In four normally contracting areas and 12 hypokinetic areas, neither fibrosis nor early changes of myocardial damage was evident. In contrast, of eight akinetic areas there was more than 50 per cent muscle loss in four and from 30 to 35 per cent muscle loss in three, in only one area was there less than 10 per cent muscle loss. Of 12 dyskinetic zones there was more than 75 per cent muscle loss in 10 zones, 35 per cent in one and no pathologic abnormalities in one. Epicardial electrograms were obtained from 35 areas in 29 patients. Of 10 normally contracting ventricles, in one, pathologic Q waves were demonstrated only over the inferior area. Progressive increases in the severity of asynergy were associated with a progressive increase in frequency of initial abnormal Q waves. In only one of nine hypokinetic areas were epicardial Q waves exhibited, but they were present in six of 10 akinetic and five of six dyskinetic areas. Both histopathologic and electrographic data were available from 20 asynergic areas in 16 patients. Initial epicardial R waves were associated with normal biopsy specimens in seven of eight hypokinetic areas. Of seven akinetic areas, initial R waves were associated with 30 to 35 per cent muscle loss in three; of four areas with initial Q waves, there was a 35 per cent muscle loss in one and more than 50 per cent muscle loss in three. Similarly, of five dyskinetic segments, a QS pattern was associated with more than 75 per cent fibrosis in four. In one dyskinetic area there was an intial R wave in association with a normal appearing biopsy specimen. In summary, a good correlation exists between the severity of asynergy by ventriculography, the degree of muscle loss and the presence of epicardial Q waves. However, a significant amount of histologically and electrographically normal myocardium may be present even in severely asynergic areas.

Correlation of pathologic Q waves on the standard electrocardiogram and the epicardial electrogram of the human heart.

SUMMARY To evaluate the relationship between abnormal Q waves on the standard ECG and localized ventricular excitation, unipolar epicardial electrograms were recorded over the left ventricle during aortocoronary bypass surgery in 36 patients. Of 20 without standard ECG Q waves, six had abnormal epicardial Q waves, three anteriorly and three inferiorly. Of 16 patients with standard ECG Q waves, four had both precordial and anterior epicardial Q waves while seven had Q waves in leads III and aVF and inferior epicardial Q waves. Three of the 14 had Q waves in both precordial and inferior leads of the ECG but epicardial Q waves only from the antero-apical region in two and only from the inferior wall in one. Two patients with Q waves in both III and aVF had no epicardial Q waves. Thus, the standard electrocardiogram underestimates epicardial Q waves. If Q waves are present in the standard ECG, they correlate with the presence, although not invariably the location of Q waves on the epicardial electrogram.

The effect of severity of coronary artery obstructive disease and the coronary collateral circulation on local histopathologic and electrographic observations in man.

Abstract The relationship between both angiographically defined proximal coronary obstructions of varying severity and coronary collaterals and the subserved left ventricular myocardium in living man is incompletely understood. Therefore, their electrophysiologic and histopathologic characteristics were evaluated in 48 patients at the time of open heart surgery. Of 28 areas supplied by ≥90 per cent obstructed arteries, the histopathology in 12, based on local biopsy specimens, was normal; in the remaining 16 there was significant muscle loss. In contrast, of five areas with Epicardial electrograms recorded from 55 areas with ≥90 per cent obstruction showed R waves in 42 and Q waves in 13. Of 24 areas with 90 per cent obstructions without collaterals, 10 were normal whereas 11 showed muscle loss. Similarly, in 16 areas with collaterals, epicardial electrograms showed R waves in 11 and Q waves in five; whereas of 39 without collaterals, there were R waves in 31 and Q waves in eight. Thus, ≥ 90 per cent coronary obstructive lesions are associated with both more muscle loss and epicardial Q waves than lesser obstructions. No beneficial effect of collaterals was demonstrable.

Traumatic coronary artery fistula.

Coronary artery fistulas can occur in patients who survive cardiac trauma. We report one such case with development of a right coronary artery-right atrial fistula 2 years after injury. The literature shows that surgical correction should be performed before the development of incapacitating symptoms (angina, pulmonary hypertension, congestive heart failure). Proximal and distal ligation of the affected coronary artery with distal bypass grafting is the recommended surgical procedure. Other procedures have led to recurrence of the fistula.

Pathophysiologic Significance of S-T and T Wave Abnormalities in Patients With The Intermediate Coronary Syndrome

The frequent association of new ST-T wave changes without Q waves in the surface electrocardiogram of patients with the intermediate coronary syndrome necessitates a better understanding of the pathophysiologic significance of this finding. A previous study in patients with stable coronary artery disease indicated that the surface electrocardiogram is insensitive in detecting epicardial Q waves. This relation was evaluated in 21 patients with the intermediate syndrome, characterized by recurrent chest pain at rest associated with significant new S-T or T wave abnormalities, or both, and no new Q waves in the surface electrocardiogram at the time of open heart coronary bypass surgery. Unipolar electrograms were recorded from the epicardial surface of the left ventricle before the bypass procedure. In 19 patients, epicardial electrograms revealed initial R waves over areas of the left ventricle in which the acute S-T and T wave abnormalities were evident in the surface electrocardiogram. Two patients had epicardial Q waves (one laterally and one inferiorly). In seven patients, a transmural biopsy specimen was also obtained from the ischemic area. All showed histologically normal myocardium without evidence of early inflammatory or necrotic tissue. Of the 19 patients discharged, only one demonstrated new postoperative Q waves that had been detected by epicardial recordings before bypass. In summary, patients with the intermediate syndrome exhibiting S-T or T wave abnormalities, or both without new Q waves in the surface electrocardiogram generally do not have Q waves either in the intraoperative epicardial or postoperative surface electrocardiogram. In addition, no histopathologic abnormalities are apparent in biopsy specimens taken from the ischemic area.

Relationship between myocardial fibrosis and epicardial and surface electrocardiogram Q waves in man

Summary The extent of transmural loss of myocardium in man which results in both the development and duration of Q waves on local electrocardiograms (ECGs) and the surface ECG is incompletely understood. Accordingly, at the time of open heart surgery, epicardial electrograms and transmural biopsies from the same site were obtained in 18 patients (19 sites). Of nine areas with epicardial R waves, eight were histologically normal while one had only Biopsies obtained from twelve areas were reflected by a normal QRS on the corresponding leads of the surface ECG. Eight biopsies were normal while three demonstrated less than 50% involvement. Only one had more than 50% transmural muscle loss in the zone corresponding to the ECG localization. Of seven biopsies obtained from areas with associated pathologic surface ECG Q waves, five had greater than 50% transmural loss. Thus, a quantitative relationship appears to exist between the amount and location of myocardial fibrosis and both the presence and duration of Q waves on epicardial electrograms. This relationship also appears to hold to a somewhat lesser degree with Q waves exhibited on the surface ECG.

Anomaly of the aortic arch: A case report

A case of the anomaly of the aortic arch was presented. The case showed subclavian steal syndrome due to the hypoplastic left subclavian artery associated with the double aortic arch with the obliterated left aortic arch. The hypoplastic left subclavian artery was replaced with the Dacron tube graft and the obliterated left arch was divided. Subclavian steal disappeared and the patient is in good condition at the present time.