The protective effects of nitroglycerin on isometric exercise
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ABSTRACTS THE CARDIOVASCULAR IMPLICATIONS OF RETINAL ARTERY OCCLUSION Herbert E. Cohen, MD; Lawrence E. Meltzer, MD, FACC; Harold G. Scheie, MD; Myron W. Frederic, MD; Arthur G. Baker, MD; Ernest B. Go, MD, Presbyterian- University of Pennsylvania Medical Center, Philadelphia, Pa Thrombosis has previously been accepted as the etiology of retinal artery occlusion (RAO). The validity of this concept was tested by a prospective multidisciplinary clinical study of 25 cases of RAO. 18 cases were caused by embolism, and only 7 cases were attributed to thrombosis. Funduscopic ex- amination revealed definite embolic material (calcium, cho- lesterol or platelet plug) in 9. Probable emboli were diagnosed in 9 others by a history or prior embolism and the identifi- cation of a potential source of embolic material. The emboli arose from previously unrecognized carotid artery stenosis (CAS) in 12, calcific aortic valve stenosis (CAVS) in 4 and both CAS and CAVS in 2. CAS angiograms showed unilateral carotid atherosclerotic disease in 6 and bilateral disease in 4; 8 had severe and 2 had mild stenotic lesions; 2 had ulcerated atherosclerotic plaques. CAVS patients showed little evidence of congestive heart failure, syncope or angina, but 3 had prior (?embolic) myocardial infarctions. 21 RAO patients had atherosclerotic risk factors, and 11 had one or more manifes- tations of systemic vascular disease. 8 patients developed new systemic vascular complications during the average 9 month follow-up period; 2 of these were embolic. In summary, RAO is not merely an ocular problem. Most RAO are due to embolism rather than thrombosis. RAO is a presenting sign of previously unrecognized CAS or CAVS, and it is a warning of impending vascular accidents. ELIMINATION OF THE NEED FOR ANTICOAGLIIATION FOLLOWING MITRAL VALVE REPLACEMENT Lawrence H. Cohn, M.D., F.A.C.C., and John .I.Collins, Jr., M.D., F.A.C.C., Harvard Medical School and Peter Bent Brigham Hospital, Boston, Massachusetts Patients with chronic atria1 fibrillation and enlarged left atria represent a high risk group for thromboembo- lism after mitral valve replacement (MVR). The Hancock porcine valve, stabilized with glutaraldehyde, has been used in 91 patients for mitral, aortic and multiple valve replacement with a 2% operative mortality and 3.5% late mortality. The incidence of thromboembolism was l/91 (1%) without anticoagulation. Thirty patients with chronic atria1 fibrillation under went MVR and have been followed from 4 to 33 months, 16.2. There was a zero incidence of postoperative throm- boemboli in this group despite no anticoagulation after an initial &week postoperative course of wafarin. The total number of embolus-free patient months was 486. The Hancock porcine mitral valve should be considered for patient* with a high risk of thromboembolism partic- ularly if they have been in chronic atria1 fibrillation. SURGICAL MANAGEMENT OF INIERRUPTED AORTIC ARCH Ruth L. Collins, MD, Macdonald Dick, MD, Lucy Parisi- Buckley, MD, Donald C. Fyler, MD, Aldo R. Castaneda, MD, Children's Hospital Medical Center, Boston, Mass. The five year experience of the New England Regional Infant Cardiac Program in twenty-nine patients with inter- rupted aortic arch (IAA) was reviewed. Twelve infants were Type A (preductile interruption), nine were Type B (left cormnoncarotid-left subclavian artery interruption), five were Type C (right innominate-left cofmnoncarotid artery interruption), and three were not classified. All had major associated cardiac abnormalities: patent ductus arteriosus, twenty-seven; ventricular septal defect (VSD), twenty-two; hypoplastic left heart, eight; d-transposition of the great arteries (d-T(X), three; single ventricle, three. Seventy-nine percent (23/29) underwent surgery; all operated patients had patent ductus arteriosus liga- tion*. Nine of these had additional palliative operations: three, simple pulmonary artery banding (PAB), and six, combined PAB and pulmonary artery to descending aorta grafts (PAG). Three have survived surgery for at least three years. Aortic arch reconstruction was undertaken in fourteen patient*, one of whom had been previously pal- liated (PAB and PAG), with three alive at ages 4 months (2)s and 4 years (1). All three, however, continue to have congestive heart failure, recurrent pulmonary infec- tions, and growth failure. Six of the twenty-nine pa- tients did not have surgery, five of whom died before ten days of age. One with d-TGA and VSD is alive at four years of age. Although various procedures have been tried in these very ill neonates, our expereince suggests that both palliative and reconstructive operations are less than optimal in achieving satisfactory clinical results. THE PROTECTIVE EFFECTS OF NITROGLYCERIN ON ISOMETRIC Kevin Conboy, MD; Athan P. Flessas, MD; Gilbert Connelly, EXERCISE MD; Cathleen Tilney, BA; Michael D. Klein, MD; Thomas J. Ryan, MD, FACC, University Hospital, Boston, Mass. Isometric exercise is an every day activity often over- looked a* a cardiovascular stress. To determine the in- fluence of nitroglycerin(TNG) on the cardiovascular re- sponse to isometric exercise, 9 pts performed 30% hand- grip (HGP) before and 4 min. after 0.4 mg TNG suhlingual- ly, at the time of cardiac catheterization. The increment in left ventricular systolic pressure(LVSP)and HR during HGP was similar before and after TNG. However, since TNG decreased the resting LVSP and accelerated the resting HR, during HGP absolute value for LVSP was significantly low- er and the HR significantly faster. The increment in LVEDP during HGP was likewise similar before and after TNG. The resting LVEDP decreased significantly from 17 mmHg to 5 mmHg (pcO.05) following TNG and rose to a significantly lower level during HGP(mean value of 12 mmHg with TNG com- pared to a mean value of 22 mmHg prior to TNG) (p<O.O2). Neither CI nor LVSWI changed significantly during HGP pri- or to TNG. Following TNG, both parameters decreased sig- nificantly at rest (C.I. = 1.97 L/min/M2, LVSWI = 43 gm-M/ beat/M2)and rose to pre TNG levels during HGP (C.I. = 2.71 L/min/M', LVSMI = 55 gm-M/beat/M2). While TNG does not alter the pressor or chronotropic effects of HGP, it does permit patients to engage in a given isometric effort at a significantly lower LVEDP and systemic pressure. These decreases in preload and after load clearly benefit the patient with coronary artery disease. 128 January 1975 The American Journal of CARDIOLOGY Volume 35
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Transcript of The protective effects of nitroglycerin on isometric exercise
ABSTRACTS
THE CARDIOVASCULAR IMPLICATIONS OF RETINAL ARTERY OCCLUSION Herbert E. Cohen, MD; Lawrence E. Meltzer, MD, FACC; Harold G. Scheie, MD; Myron W. Frederic, MD; Arthur G. Baker, MD; Ernest B. Go, MD, Presbyterian- University of Pennsylvania Medical Center, Philadelphia, Pa
Thrombosis has previously been accepted as the etiology of retinal artery occlusion (RAO). The validity of this concept was tested by a prospective multidisciplinary clinical study of 25 cases of RAO. 18 cases were caused by embolism, and only 7 cases were attributed to thrombosis. Funduscopic ex- amination revealed definite embolic material (calcium, cho- lesterol or platelet plug) in 9. Probable emboli were diagnosed in 9 others by a history or prior embolism and the identifi- cation of a potential source of embolic material. The emboli arose from previously unrecognized carotid artery stenosis (CAS) in 12, calcific aortic valve stenosis (CAVS) in 4 and both CAS and CAVS in 2. CAS angiograms showed unilateral carotid atherosclerotic disease in 6 and bilateral disease in 4; 8 had severe and 2 had mild stenotic lesions; 2 had ulcerated atherosclerotic plaques. CAVS patients showed little evidence of congestive heart failure, syncope or angina, but 3 had prior (?embolic) myocardial infarctions. 21 RAO patients had atherosclerotic risk factors, and 11 had one or more manifes- tations of systemic vascular disease. 8 patients developed new systemic vascular complications during the average 9 month follow-up period; 2 of these were embolic. In summary, RAO is not merely an ocular problem. Most RAO are due to embolism rather than thrombosis. RAO is a presenting sign of previously unrecognized CAS or CAVS, and it is a warning of impending vascular accidents.
ELIMINATION OF THE NEED FOR ANTICOAGLIIATION FOLLOWING MITRAL VALVE REPLACEMENT Lawrence H. Cohn, M.D., F.A.C.C., and John .I. Collins, Jr., M.D., F.A.C.C., Harvard Medical School and Peter Bent Brigham Hospital, Boston, Massachusetts
Patients with chronic atria1 fibrillation and enlarged left atria represent a high risk group for thromboembo- lism after mitral valve replacement (MVR). The Hancock porcine valve, stabilized with glutaraldehyde, has been used in 91 patients for mitral, aortic and multiple valve replacement with a 2% operative mortality and 3.5% late mortality. The incidence of thromboembolism was l/91 (1%) without anticoagulation.
Thirty patients with chronic atria1 fibrillation under went MVR and have been followed from 4 to 33 months, 16.2. There was a zero incidence of postoperative throm- boemboli in this group despite no anticoagulation after an initial &week postoperative course of wafarin. The total number of embolus-free patient months was 486.
The Hancock porcine mitral valve should be considered for patient* with a high risk of thromboembolism partic- ularly if they have been in chronic atria1 fibrillation.
SURGICAL MANAGEMENT OF INIERRUPTED AORTIC ARCH Ruth L. Collins, MD, Macdonald Dick, MD, Lucy Parisi- Buckley, MD, Donald C. Fyler, MD, Aldo R. Castaneda, MD, Children's Hospital Medical Center, Boston, Mass.
The five year experience of the New England Regional Infant Cardiac Program in twenty-nine patients with inter- rupted aortic arch (IAA) was reviewed. Twelve infants were Type A (preductile interruption), nine were Type B (left cormnon carotid-left subclavian artery interruption), five were Type C (right innominate-left cofmnon carotid artery interruption), and three were not classified. All had major associated cardiac abnormalities: patent ductus arteriosus, twenty-seven; ventricular septal defect (VSD), twenty-two; hypoplastic left heart, eight; d-transposition of the great arteries (d-T(X), three; single ventricle, three. Seventy-nine percent (23/29) underwent surgery; all operated patients had patent ductus arteriosus liga- tion*. Nine of these had additional palliative operations: three, simple pulmonary artery banding (PAB), and six, combined PAB and pulmonary artery to descending aorta grafts (PAG). Three have survived surgery for at least three years. Aortic arch reconstruction was undertaken in fourteen patient*, one of whom had been previously pal- liated (PAB and PAG), with three alive at ages 4 months
(2)s and 4 years (1). All three, however, continue to have congestive heart failure, recurrent pulmonary infec- tions, and growth failure. Six of the twenty-nine pa- tients did not have surgery, five of whom died before ten days of age. One with d-TGA and VSD is alive at four years of age. Although various procedures have been tried in these very ill neonates, our expereince suggests that both palliative and reconstructive operations are less than optimal in achieving satisfactory clinical results.
THE PROTECTIVE EFFECTS OF NITROGLYCERIN ON ISOMETRIC
Kevin Conboy, MD; Athan P. Flessas, MD; Gilbert Connelly, EXERCISE
MD; Cathleen Tilney, BA; Michael D. Klein, MD; Thomas J. Ryan, MD, FACC, University Hospital, Boston, Mass.
Isometric exercise is an every day activity often over- looked a* a cardiovascular stress. To determine the in- fluence of nitroglycerin(TNG) on the cardiovascular re- sponse to isometric exercise, 9 pts performed 30% hand- grip (HGP) before and 4 min. after 0.4 mg TNG suhlingual- ly, at the time of cardiac catheterization. The increment in left ventricular systolic pressure(LVSP)and HR during HGP was similar before and after TNG. However, since TNG decreased the resting LVSP and accelerated the resting HR, during HGP absolute value for LVSP was significantly low- er and the HR significantly faster. The increment in LVEDP during HGP was likewise similar before and after TNG. The resting LVEDP decreased significantly from 17 mmHg to 5 mmHg (pcO.05) following TNG and rose to a significantly lower level during HGP(mean value of 12 mmHg with TNG com- pared to a mean value of 22 mmHg prior to TNG) (p<O.O2). Neither CI nor LVSWI changed significantly during HGP pri- or to TNG. Following TNG, both parameters decreased sig- nificantly at rest (C.I. = 1.97 L/min/M2, LVSWI = 43 gm-M/
beat/M2)and rose to pre TNG levels during HGP (C.I. = 2.71 L/min/M', LVSMI = 55 gm-M/beat/M2). While TNG does not alter the pressor or chronotropic
effects of HGP, it does permit patients to engage in a given isometric effort at a significantly lower LVEDP and systemic pressure. These decreases in preload and after load clearly benefit the patient with coronary artery disease.
128 January 1975 The American Journal of CARDIOLOGY Volume 35
