A two-dimensional analysis of regional myocardial function in the dog

1983 ◽  
Vol 61 (8) ◽  
pp. 920-926 ◽  
Author(s):  
Hideo Nomura ◽  
Kazuhiko Nagata ◽  
Yoshihiro Futamura ◽  
Yoshiyuki Hama ◽  
Iwao Sotobata
Keyword(s):  
Cardiac Function ◽  
Surface Area ◽  
Dimensional Analysis ◽  
Myocardial Function ◽  
Left Ventricular ◽  
Segment Length ◽  
Myocardial Segment ◽  
Two Dimensional ◽  
Ventricular Contraction ◽  
Regional Myocardial Function

The pattern of left ventricular contraction or relaxation is not uniform and also changes depending on hemodynamic states. Accordingly, the measurement of myocardial segment length only may have limitations for the analysis of regional myocardial function, and a two-dimensional analysis of regional myocardial function was developed and characterized by utilizing measurement of regional myocardial surface area on the epicardial surface. In eight anesthetized open-chest dogs, the relationship between regional myocardial function and total cardiac function was examined. The extent of the reduction of regional myocardial surface area during the ejection phase or during the systolic phase correlated more closely with stroke volume over wide ranges of left ventricular end-diastolic pressure, aortic pressure, left ventricular contractility, and heart rate (r = 0.75–0.96) than the shortening of myocardial segment length alone. Thus, the results demonstrated that regional myocardial function estimated by the measurement of regional myocardial surface area represents total cardiac function more accurately than myocardial segment length over wide ranges of hemodynamic states despite the changes in the left ventricular contraction and relaxation pattern.

Improvement by isosorbide dinitrate of exercise-induced regional myocardial dysfunction

1980 ◽  
Vol 239 (3) ◽  
pp. H399-H405
Author(s):  
T. Kumada ◽  
K. P. Gallagher ◽  
M. Miller ◽  
M. McKown ◽  
F. White ◽  
...  
Keyword(s):  
Isosorbide Dinitrate ◽  
Myocardial Function ◽  
Myocardial Dysfunction ◽  
Left Ventricular ◽  
Segment Length ◽  
Wall Thickening ◽  
Regional Myocardial Function ◽  
Exercise Induced ◽  
Coronary Obstruction ◽  
Control Exercise

Sonomicrometry was used in 10 conscious dogs to measure regional segment length and dynamic wall thickness by telemetry in a zone supplied by the left circumflex coronary artery after implantation of an ameroid constrictor. When coronary obstruction was nearly complete and collaterals had developed (24-42 days), control exercise and exercise runs after oral isosorbide dinitrate were carried out. During control runs, significant increases occurred in hemodynamic parameters, and percent shortening in normal segments increased (P < 0.01). During the repeat runs after isosorbide dinitrate, there were smaller increases in left ventricular systolic and end-diastolic pressures and significantly reduced end-diastolic dimensions. In addition, percent wall thickening and percent segment shortening in the ischemic zone did not deteriorate significantly during exercise. In this animal model, which appears to mimic chronic single-vessel coronary heart disease, isosorbide dinitrate can prevent exercise-induced deterioration of regional myocardial function.

Effect of arterial blood pressure and ventilation gases on cardiac depression induced by coronary air embolism

1994 ◽  
Vol 77 (4) ◽  
pp. 1896-1902 ◽  
Author(s):  
J. H. van Blankenstein ◽  
C. J. Slager ◽  
L. K. Soei ◽  
H. Boersma ◽  
P. D. Verdouw
Keyword(s):  
High Pressure ◽  
Myocardial Function ◽  
Air Embolism ◽  
Low Pressure ◽  
Left Ventricular ◽  
Segment Length ◽  
Air Bubbles ◽  
Regional Myocardial Function ◽  
Cardiac Depression ◽  
Arterial Blood

In this study the time course of cardiac depression after selective intracoronary injection of air bubbles was investigated in six anesthetized pigs (30 +/- 2 kg) with different mixtures of ventilation gases and different mean arterial blood pressures (MAP). Air bubbles of 150 microns diam were injected into the left anterior descending coronary artery (LADCA) in a volume of 2 microliters/kg body wt. In each animal an injection of air bubbles was applied during ventilation with N2-O2 and a MAP of 77 +/- 3 mmHg (N2-O2/low pressure) or 111 +/- 3 mmHg (N2-O2/high pressure) and during ventilation with pure O2 and a MAP of 77 +/- 3 mmHg (O2/low pressure) or 110 +/- 3 mmHg (O2/high pressure). Systemic hemodynamic variables such as left ventricular pressure, its peak first derivatives, and MAP changed < 10% after injection of air bubbles. During N2-O2/low pressure, systolic segment length shortening in the LADCA region (SS-LADCA) decreased from baseline and did not return to baseline within the 10 min after injection of air bubbles. During N2-O2/high pressure and O2/low pressure, SS-LADCA was decreased between 60 and 120 s, whereas for O2/high pressure this period was from 60 to 90 s. By calculating the time integral of the deviation from baseline of SS-LADCA, it could be demonstrated that the depression of regional myocardial function was less severe during O2/high pressure and O2/low pressure than during N2-O2/low pressure. We conclude that, when coronary air embolism occurs during hypertension and during ventilation with pure O2 instead of a normal N2-O2 mixture, the resulting depression of regional myocardial function is reduced.

Muscle metabolism and cardiac function of the myopathic hamster following training

1977 ◽  
Vol 43 (6) ◽  
pp. 936-941 ◽  
Author(s):  
W. L. Sembrowich ◽  
M. B. Knudson ◽  
P. D. Gollnick
Keyword(s):  
Skeletal Muscle ◽  
Cardiac Function ◽  
Myocardial Function ◽  
Cardiac Contractility ◽  
Muscle Metabolism ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Treadmill Running ◽  
Succinate Dehydrogenase Activity ◽  
Positive Effect

The effect of 18 wk of treadmill running on skeletal muscle metabolism and myocardial function of normal and myopathic hamsters was examined. BIO 14.6 hamsters could tolerate an exercise intensity of about 18 m/min for 40 min, 5 days/wk. Further increases in speed or number of bouts per day resulted in a falloff in performance. Normal hamsters could tolerate higher speeds and longer exercise bouts. Exercise did not change the severity of lesions of either the heart or skeletal muscle of the myopathic hamsters. A training effect was evidenced by increased succinate dehydrogenase activity in the soleus muscle. Cardiac function was evaluated as contractility measured from left ventricular pressure curves and expressed as (dP/dt)/kP. The results suggested that cardiac contractility was not as severely depressed in the trained BIO 14.6 strain of hamsters as in nontrained controls. However, (dP/dt)/kP was lower in the trained myopathic animals than in normal hamsters. ATP, CP, and glycogen levels were lower in myopathic hamsters with the lowest values occurring in the trained group. These data demonstrate that the BIO 14.6 strain of hamster can tolerate exercise training and that such training may have a positive effect on cardiac function.

Abstract 2569: Tissue Doppler Imaging In The Evaluation Of Infarcted Segmental Myocardial Function In Stemi Reperfused Patients: Correlation With Myocardial Blush Grade.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Elena Inches ◽  
Massimo Mancone ◽  
Gennaro Sardella ◽  
Raffaele Scardala ◽  
Riccardo Colantonio ◽  
...  
Keyword(s):  
Tissue Doppler Imaging ◽  
Myocardial Function ◽  
Systolic Function ◽  
Tissue Doppler ◽  
Left Ventricular ◽  
Doppler Imaging ◽  
Primary Pci ◽  
Regional Myocardial Function ◽  
Predictive Index ◽  
Myocardial Blush Grade

Background: The myocardial blush grade (MBG) during primary-PCI predicts long-term recovery of left ventricular function. Tissue Doppler imaging (TDI) quantitatively assess regional myocardial function by measuring systolic strain (SS). No data are available on the correlation between MBG and the infarcted segmental systolic function by TDI in STEMIpts. Methods: We evaluated 40 STEMI pts, divided in four groups (MBG 0; MBG 1; MBG 2; MBG 3) 10 pts for each goup. Primary PCI was performed according to current standard guidelines. Coronary angiograms were analyzed off-line by two expert interventional cardiologists in a blinded manner. MBG were estimated visually. Sixteen-segments model was applied and regional myocardial function was evaluated, immediately after primary PCI, by measuring SS by TDI . Only SS value in infarcted segments was correlated with the MBG. Results: No significative difference was observed between groups except for family history of CAD that was higher in MBG 2 group. Mean ejection fraction (39,1 ± 8,8%) and mean symptoms to balloon time(4.3 ± 1.6 h ) was similar in the population. 136 infarcted segments were studied by TDI. A significant direct correlation between the MBG and the SS (r=0.79; p<0.005) (Fig.1 ). We also observed a significative difference (p<0.005) between mean SS in pts with MBG ≤0 –1 (7.6 ± 2.4%) and in pts with MBG≥2–3(22.6 ± 5.2). Conclusions: Abnormal values of SS was observed in infarcted segments. The significant correlation observed between the MBG and SS may demonstrate that MBG represent an important predictive index not only of good reperfusion but also of rapid segmental function recovery; similarly an evaluation of SS after primary PCI could be useful to evaluate if primary percutaneus reperfusion has been effective or not.

Effects of arterial hypertension on myocardial recovery after ischemic injury

1992 ◽  
Vol 263 (2) ◽  
pp. H559-H564 ◽  
Author(s):  
J. R. Elbeery ◽  
R. F. Williams ◽  
J. S. Rankin ◽  
D. D. Glower ◽  
D. C. Sabiston ◽  
...  
Keyword(s):  
Arterial Hypertension ◽  
Systolic Function ◽  
Ischemic Injury ◽  
Left Ventricular ◽  
Segment Length ◽  
Myocardial Segment ◽  
Stroke Work ◽  
Myocardial Recovery ◽  
Length Relationship ◽  
Injured Myocardium

Although improved surgery, angioplasty, and thrombolysis have made early revascularization of ischemic myocardium commonplace, the effects of arterial hypertension on myocardial recovery remain unclear. Therefore eight conscious dogs were instrumented to measure left ventricular transmural pressure and myocardial segment length in the left anterior descending (LAD) coronary distribution. Reversible ischemic injury was produced by two 15-min LAD occlusions separated by 4 days of reperfusion, with each dog randomly receiving either phenylephrine or placebo infusion for 30 min beginning 1 h after reperfusion. With ischemia, systolic myocardial performance fell to 14.3 +/- 3.7% of control and required greater than 48 h to recover. Compared with placebo, phenylephrine significantly depressed recovery of systolic function assessed by systolic shortening (57 +/- 12 vs. 85 +/- 13% control) or the area under the stroke work vs. end-diastolic length relationship (62 +/- 14 vs. 93 +/- 7% control) (both P less than 0.05). These data imply that ischemically injured myocardium is highly sensitive to arterial hypertension and that ventricular loading is a major determinant of the rate of myocardial recovery.

One-day cold perfusion of bimakalim and butanedione monoxime restores ex situ cardiac function

1996 ◽  
Vol 271 (5) ◽  
pp. H1884-H1892 ◽  
Author(s):  
D. F. Stowe ◽  
B. M. Graf ◽  
S. Fujita ◽  
G. J. Gross
Keyword(s):  
Cardiac Function ◽  
Myocardial Function ◽  
Left Ventricular Pressure ◽  
Katp Channels ◽  
Left Ventricular ◽  
Ex Situ ◽  
Control Group ◽  
Cardiac Efficiency ◽  
Time Control ◽  
Butanedione Monoxime

Bimakalim (Bim), an opener of ATP-sensitive K+ (KATP) channels, was given alone or with 2,3-butanedione monoxime (BDM), a reversible uncoupler of contractility, to protect myocardial function during 1 day of hypothermia. Left ventricular pressure (LVP), coronary flow (CF), percent O2 extraction (%O2E), and cardiac efficiency were measured in 96 isolated, perfused guinea pig hearts divided into seven groups: 1) cold control (no drugs); 2) BDM; 3) Bim; 4) BDM + Bim; 5) BDM + glibenclamide (Glib, a blocker of KATP channels); 6) BDM + Bim + Glib; and 7) time control (6 h warm perfusion only). Drugs were given before, during, and initially after 22 h of low CF at 3.8 degrees C. At 26 h (cold groups) or 4 h (warm group) LVP (mmHg; means +/- SE) was similar for time control (94 +/- 4) and BDM + Bim (92 +/- 4) groups, lower and equivalent in the BDM (65 +/- 7) and BDM + Bim + Glib (64 +/- 7) groups, but LVP was higher than in the Bim group (46 +/- 3), and lowest in the cold control (30 +/- 8) group. In addition, only in the BDM + Bim group were basal CF, %O2E, and cardiac efficiency returned to values obtained in the time control group. Epinephrine increased LVP to that of the time control (106 +/- 3) group only in the BDM + Bim group (106 +/- 3) after hypothermia, and CF increases with adenosine, 5-hydroxytryptamine, and nitroprusside were similar to that of the time control group only in the BDM + Bim group after hypothermia. All of the effects of Bim were reversed by Glib. These results indicate that Bim, given with BDM, effectively preserves myocardial function and metabolism as well as inotropic and vasodilatory reserve during long-term hypothermic preservation as if the 1-day hypothermic state had not been instituted. Because the beneficial effects of Bim are blocked by Glib, the protective effect of Bim likely results from maintained KATP channel opening. Treatment with exogenous KATP openers may prove useful in preserving cardiac function in the transplanted heart.

Myocardial protection from ischemic arrest: potassium and verapamil cardioplegia

1981 ◽  
Vol 240 (3) ◽  
pp. H326-H335 ◽  
Author(s):  
W. W. Pinsky ◽  
R. M. Lewis ◽  
J. B. McMillin-Wood ◽  
H. Hara ◽  
C. J. Hartley ◽  
...  
Keyword(s):  
Calcium Transport ◽  
Myocardial Protection ◽  
Myocardial Function ◽  
Myocardial Dysfunction ◽  
Left Ventricular ◽  
The Other ◽  
Myocardial Segment ◽  
Intracoronary Infusion ◽  
Hemodynamic Function ◽  
And Function

Prolonged normothermic myocardial ischemic arrest results in myocardial dysfunction. This study has investigated the technique of preserving myocardial function by a single bolus intracoronary infusion of combination potassium and verapamil at the onset of ischemic arrest. Sixty-one dogs underwent cardiopulmonary bypass with 60 min of ischemic arrest: 25 received no myocardial protection, 12 received a single intracoronary bolus of KCl, 12 received combination verapamil and KCl, and 12 received verapamil alone. Following the ischemic arrest, hearts protected by combination of potassium and verapamil demonstrated better survival evidenced by the ability of all 12 dogs to resume normal hemodynamic function. The hemodynamic function in the combination potassium and verapamil group also demonstrated better cardiac output, left ventricular dF/dt, and myocardial segment shortening than survivors in the other groups. Subsarcolemmal (SSL) and intermyofibrillar IMF) mitochondria were isolated from these hearts and function evaluated. NADH-linked oxygen consumption was impaired as was calcium transport in the SSL from unprotected ischemic hearts. Intermyofibrillar mitochondria were not different from control or sham. The hearts protected by verapamil and potassium demonstrated normal mitochondrial function.

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