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Hemodynamics during rest and exercise in patients with mixed aortic stenosis and insufficiency
ABSTRACTS
below 2,200 set+ are seen in myocardial dysfunction, sometimes before t,he ejection fraction begins to decrease. These measurements, which can be obtained in minutes
after catheterization, appear to be useful in the total assessment of t.he condit,ion of the individual pat.ient studied in a clinical laborat,ory.
Computer Analyses and Telephone Transmission of Pacemaker Artifact Information DORIS
J. W. ESCHER,
NORMON SOLOMON, Bronx, New York
MD,
FACC/SEYMOUR
MD and SRIRAMALU
FURMAN, NAIDU,
MD, FACC/BRYAN
PARKER
MD
Programmed follow-up st’udies of patients after implantation of cardiac pacemakers is the major recourse against unant.icipated catastrophic failures. In a series, dating from 1961, of approximately 470 such pat,ient,s, 375 have been followed up since 1967 by electronic analysis 3 to 4 t*imes a year of pacemaker artifact rate, contour, amplitude and pulse duration, with mandat’ory change of the pulse generator at 24 to 30 months (depending upon statistical experience with specific systems). Of premature failures, 95% have been of the pulse generator, 10% under 1 or after 3 years, 80% in the second yea.r. Overall sudden failures of 16% have been reduced to 12% in the last year.
Computer programming with trend analyses for each patient of decay rate or unusual changes and comparative analyses of system groups allows better prediction of individual and group performance. Further safety would be insured by more frequent, examination. Where t,his becomes a logist,i,c problem, use of newly developed instrumentation, a.llowing transmission of artifact rate and possibly artifact amplitude and duration by signals over telephone lines from home to follow-up clinic, supplements or reduces direct visits. Tape-recorded transmissions can be transferred to visual displays or fed into the computer to become part of the ongoing record.
Hemodynamics During Rest and Exercise in Patients with Mixed Aortic Stenosis and Insufficiency PHILIP 0. ElTINGER, MD/MARTIN J. FRANK, MD, FACC and GILBERT E. LEVINSON, MD, FACC Jersey City, New Jersey
Recent work by others has shown that many patients with mixed aortic stenosis and regurgitation exhibit a decrease or no change in the aortic systolic gradient during exercise despite increased systemic flow. It has been suggested that the Gorlin formula may, therefore, sometimes be inapplicable because the stenotic aortic orifice is, or behaves as if it were, inconstant in size. However, studies reported from our laboratory have shown that regurgitant fraction falls during exercise in pure aortic regurgitation while total flow is remarkably constant. The present study investigated this problem in 9 patients with mixed aortic lesions. Regurgitation was measured during rest and exercise by simultaneous upstream and downstream sampling with the use of continuous indicator infusions. Hea,rt rate increased and peripheral resistance decreased in every patient, but the aortic valve gradient, (mean 42 + 10
Maximal Contractile Element Velocity (V ,,,& an Index of Contractile State in Man HERMAN L. FALSETTI, MD/ROBERT and IVAN L. BUNNELL, MD Buffalo, New York
as
E. MATES, PhD/DAVID
The maximal, no-load velocity for the contractile element (V,,.) was estimated in 45 patients. The patients included 17 with normal left ventricular dynamics; 8 with volume
94
mm Hg) did not change significantly. Increased forward flow (mean 4.52 + 0.34 at rest and 6.66 + 0.44 liter/min with exercise, P < 0.01) was balanced by decreased regurgitation (mean 4.54 % 1.17 and 2.81 r+ 1.12 liter/min, P = 0.05), and total flow did not change significantly. The systolic ejection period declined significantly, but systolic and diastolic seconds per minut.e changed very little. The mean aortic valve area was 1.8 +- 0.3 cmz bot#h at rest and during exercise. This study confirms the necessity for measurement’s of tot.al valve flow in eva.luation of mixed valve lesions. It also demonst’rates that (1) exercise reduces the regurgitant fraction in mixed aortic lesions as it does in pure aortic insufficiency; (2) this effect is not due to a shortened diastolic time per minute but must reflect an altered relation of peripheral resistance to ventricular compliance; and (3) the stenotic aortic valve, contrary t,o recent suggestion, behaves as a fixed orifice.
G. GREENE,
MD, FACC
overload, compensated; 11 with volume overload, decompensated; 3 with pressure overload; and 6 with cardiomyopathy. Contractile element velocity (V,) during isovolumic
The
American Journal
of CARDlOLOaY
below 2,200 set+ are seen in myocardial dysfunction, sometimes before t,he ejection fraction begins to decrease. These measurements, which can be obtained in minutes
after catheterization, appear to be useful in the total assessment of t.he condit,ion of the individual pat.ient studied in a clinical laborat,ory.
Computer Analyses and Telephone Transmission of Pacemaker Artifact Information DORIS
J. W. ESCHER,
NORMON SOLOMON, Bronx, New York
MD,
FACC/SEYMOUR
MD and SRIRAMALU
FURMAN, NAIDU,
MD, FACC/BRYAN
PARKER
MD
Programmed follow-up st’udies of patients after implantation of cardiac pacemakers is the major recourse against unant.icipated catastrophic failures. In a series, dating from 1961, of approximately 470 such pat,ient,s, 375 have been followed up since 1967 by electronic analysis 3 to 4 t*imes a year of pacemaker artifact rate, contour, amplitude and pulse duration, with mandat’ory change of the pulse generator at 24 to 30 months (depending upon statistical experience with specific systems). Of premature failures, 95% have been of the pulse generator, 10% under 1 or after 3 years, 80% in the second yea.r. Overall sudden failures of 16% have been reduced to 12% in the last year.
Computer programming with trend analyses for each patient of decay rate or unusual changes and comparative analyses of system groups allows better prediction of individual and group performance. Further safety would be insured by more frequent, examination. Where t,his becomes a logist,i,c problem, use of newly developed instrumentation, a.llowing transmission of artifact rate and possibly artifact amplitude and duration by signals over telephone lines from home to follow-up clinic, supplements or reduces direct visits. Tape-recorded transmissions can be transferred to visual displays or fed into the computer to become part of the ongoing record.
Hemodynamics During Rest and Exercise in Patients with Mixed Aortic Stenosis and Insufficiency PHILIP 0. ElTINGER, MD/MARTIN J. FRANK, MD, FACC and GILBERT E. LEVINSON, MD, FACC Jersey City, New Jersey
Recent work by others has shown that many patients with mixed aortic stenosis and regurgitation exhibit a decrease or no change in the aortic systolic gradient during exercise despite increased systemic flow. It has been suggested that the Gorlin formula may, therefore, sometimes be inapplicable because the stenotic aortic orifice is, or behaves as if it were, inconstant in size. However, studies reported from our laboratory have shown that regurgitant fraction falls during exercise in pure aortic regurgitation while total flow is remarkably constant. The present study investigated this problem in 9 patients with mixed aortic lesions. Regurgitation was measured during rest and exercise by simultaneous upstream and downstream sampling with the use of continuous indicator infusions. Hea,rt rate increased and peripheral resistance decreased in every patient, but the aortic valve gradient, (mean 42 + 10
Maximal Contractile Element Velocity (V ,,,& an Index of Contractile State in Man HERMAN L. FALSETTI, MD/ROBERT and IVAN L. BUNNELL, MD Buffalo, New York
as
E. MATES, PhD/DAVID
The maximal, no-load velocity for the contractile element (V,,.) was estimated in 45 patients. The patients included 17 with normal left ventricular dynamics; 8 with volume
94
mm Hg) did not change significantly. Increased forward flow (mean 4.52 + 0.34 at rest and 6.66 + 0.44 liter/min with exercise, P < 0.01) was balanced by decreased regurgitation (mean 4.54 % 1.17 and 2.81 r+ 1.12 liter/min, P = 0.05), and total flow did not change significantly. The systolic ejection period declined significantly, but systolic and diastolic seconds per minut.e changed very little. The mean aortic valve area was 1.8 +- 0.3 cmz bot#h at rest and during exercise. This study confirms the necessity for measurement’s of tot.al valve flow in eva.luation of mixed valve lesions. It also demonst’rates that (1) exercise reduces the regurgitant fraction in mixed aortic lesions as it does in pure aortic insufficiency; (2) this effect is not due to a shortened diastolic time per minute but must reflect an altered relation of peripheral resistance to ventricular compliance; and (3) the stenotic aortic valve, contrary t,o recent suggestion, behaves as a fixed orifice.
G. GREENE,
MD, FACC
overload, compensated; 11 with volume overload, decompensated; 3 with pressure overload; and 6 with cardiomyopathy. Contractile element velocity (V,) during isovolumic
The
American Journal
of CARDlOLOaY