Transient tricuspid insufficiency: Manifestation of myocardial dysfunction in stressed newborns

Bucciarelli, Richard L.; Nelson, Robert M.; Egan, Edmund A.; Eitzman, Donald V.; Gessner, Ira H.

doi:10.1016/0002-9149(76)90544-0

Cited by 29 publications

(39 citation statements)

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“…Affected infants are more likely to have suffered peripartum asphyxia or hypoglycemia (2, 4), and to have had higher birth weights (9,20). Clinically, they exhibit cardiorespiratory failure and a murmur of atrioventricular valvular insufficiency (2,3,19,20). Evidence of myocardial ischemia during the fulminant period of heart failure has been obtained from biochemical (17), electrocardiographic (4,10,19,20) and radiological studies [cineangiography (2) and thallium myocardial imaging (10)].…”

Section: Discussionmentioning

confidence: 99%

The Regional Distribution and Determinants of Myocardial Blood Flow during Asphyxia in the Fetal Lamb

Davies

Tweed

1984

Pediatr Res

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SummaryThe syndrome of hypoxemia-related myocardial dysfunction in the newborn is generally associated with severe intrapartum asphyxia. We investigated the changes in total and regional distribution of myocardial blood flow (MBF) that occur during asphyxia and the factors that regulate MBF, in the chronically prepared, near term, fetal lamb. Studies were done in the awake, physiologically stable state 36-72 h after surgical preparation.In utero asphyxia was produced by partial cord occlusion and blood flow to fetal organs was measured by the radioactive microsphere technique. A complete set of control measurements was made, and then an occlusion loop was inflated to partially occlude the umbilical vessels. After 30-60 min of partial occlusion, all measurements were repeated. The third set of measurements was made after release of the occlusion loop. Six animals were studied and 17 sets of measurements obtained.Partial umbilical cord constriction produced a progressive asphyxia and acidosis. Cardiac output was severely depressed, although the increase in percentage of cardiac output directed to the myocardium (%F) was very significant. Release resulted in improved cardiac output and O2 and CO 2 exchange, although the metabolic acidosis was worse. No change occurred in the intramyocardial distribution of MBF during asphyxia or recovery. Total MBF was not significantly increased during asphyxia.Multiple linear regression analysis indicated that arterial oxygen saturation (Sa02) and heart rate were statistically significant predictor variables for absolute MBF, accounting for about 45% of the variation in MBF. Further analysis determined that mean arterial blood pressure, pH, P02, and Sa02 were all statistically significant univariate predictors of MBF as %F, but only Sa02 was a statistically significant multivariate predictor, accounting for about 82% of the variation in %F.

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Section: Discussionmentioning

confidence: 99%

The Regional Distribution and Determinants of Myocardial Blood Flow during Asphyxia in the Fetal Lamb

Davies

Tweed

1984

Pediatr Res

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“…Subendocardial and/ or papillary muscle ischemia appears to be the basis for the myocardial dysfunction (4,12,30,33). While coronary stenoses are present in most adults who develop myocardial ischemia, there has been no evidence of coronary stenoses in asphyxiated newborns who have expired after developing severe myocardial dysfunction (4,12,30,33). Consequently, the factor(s) that produce myocardial ischemia during birth asphyxia remain to be determined (33).…”

Section: Discussionmentioning

confidence: 99%

“…birth asphyxia (4,33,34). The demonstration of electrocardiographic Q or ST-T wave abnormalities, increased creatine phosphokinase MB activity, and decreased myocardial uptake of thallium-201 in survivors of birth asphyxia suggests an ischemic basis for the myocardial dysfunction (4,12,28,34).…”

Section: Discussionmentioning

confidence: 99%

Increased Regional Myocardial Blood Flows and Oxygen Deliveries during Hypoxemia in Lambs

Fisher

1984

Pediatr Res

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SummaryNewborn humans may develop myocardial dysfunction in conjunction with severe birth asphyxia. Subendocardial or papillary muscle ischemia appears to be the basis for the myocardial dysfunction, yet patent coronary arteries have been demonstrated in the nonsurvivors. The asphyxiated newborns also have experienced hypoxemia, which has been suggested a s the cause-of mvocardial ischemia. This studv was designed to determine the -relationship between reduced aortic blood oxygen content and blood flow a s well as oxygen delivery within different regions of the heart. Three days after surgery, we measured blood flow and oxygen delivery to the free walls and papillary muscles of the right and left ventricles, the ventricular septum, and the atria in 10 lambs, during 20-min periods in 8-10070 and 5-6% environmental oxygen concentrations. In each region of myocardium, blood flow increased linearly a s the aortic blood oxygen content decreased. The slopes of the regression lines were similar for each region of ventricular myocardium. Atrial myocardial blood flow also increased a s a linear function of the reductions in aortic blood oxygen content, but a t a slower rate than in the ventricular regions. Hypoxemia was associated with increased oxygen delivery in each region of myocardium, but the two variables were not related in a linear or quadratic fashion. The results demonstrate that isolated hypoxemia is associated with increased blood flow and oxygen delivery in the free walls and papillary muscles of the right and left ventricles, the ventricular septum, and the atria.

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“…The discrepancy between right and left ventricular stroke volume responses to arterial pressure might be even further pronounced in the stressed newborn with birth asphyxia and persistent hypoxemia prior to closure of the ductus arteriosus. There is ample clinical evidence of selective right ventricular dysfunction in this setting of neonatal hypoxemia and persistent pulmonary hypertension of the newborn (25,26).…”

Section: T I M E After Initiation Of Mechanical Ventilation ( M I N )mentioning

confidence: 99%

Fetal Lamb Ventricles Respond Differently to Filling and Arterial Pressures and to in Utero Ventilation

et al. 1987

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ABSTRACT. Right and left ventricular function were in-function curve. but differs in that it is positioned "above" the vestigated in 12 fetal lambs (127-140 days gestation) left ventricular curve. Although these experiments support the instrumented with electromagnetic flow sensors on the concept of right ventricular dominance, statistical significance ascending aorta and the main pulmonary artery, and with between the positions of the function curves was not achieved vascular catheters. Nine fetuses were equipped with a possibly because of biologic variability between animals. postductal aortic occluder and the trachea was cannulated When assessing the response to changes in arterial pressure, in eight. Control arterial blood values were pH 7.36 + 0.02 the two ventricles have been found to differ significantly (4. 5).(SD), PC02 49.3 + 2.3 torr, PO2 18.4 + 1.7 torr, and In the arterial pressure range from 20-90 tom, right ventricular hematocrit 37.3 2 4.4%. Biventricular function curves stroke volume was very negatively influenced by arterial pressure. relating stroke volume to mean right and left atrial pressure while left ventricular stroke volume was minimally affected. were generated by rapid withdrawal and reinfusion of fetal These preliminary findings indicate that the two fetal ventricles blood. Both function curves were composed of steep as-distinctly differ in their response to changes in arterial pressure. cending and plateau limbs that intersected a t a breakpoint. Animuls.Ewes of mixed breeds were bred at our institutional From early investigations on acutely instrumented, anesthe-farm to provide dated pregnancy and were brought to the labotized animals, it was concluded that the fetal ventricles have ratory Pens Several days before surgery to become accustomed similar outputs (I). Subsequent studies in chronically instru-to the surroundings. Fetuses of known gestation (123-133 days) mented, unanesthetized fetal lambs have shown a consistent were selected for right ventricular dominance under control with the Surgicul procedtrres. Ewes and fetuses underwent sterile surright ventricular output comprising 55-67% of the combined geV using protocols ~reviously described (4. 5, 7). ~n e s t h e s i a fetal cardiac output (2, 3). ~~~~l right and left ventricular stroke was induced with intravenous methohexitol and maintained with volumes have been measured separately during changes in filling 1 % halothane in nitrous oxide and oxygen. h he fetus was delivpressure produced by hemorrhage and crystalloid infusion. and ered through a midline laparotomy and hysterotomy. ~o l~v i n~l during changes in arterial pressure (4, 5). These studies have catheters (V-5, 1.3 mm O D or V-8 1.7 m m OD, Bolab Inc., ~a k e shown that the right ventricular function curve relating stroke Havasu City. AZ) were placed in the right carotid artery and volume to atrial pressure has a shape similar to the left ventricular advanced to the brachiocepha1ic artery and in the right Jugular vein and advanced to the right atrium. The trach...

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Transient tricuspid insufficiency: Manifestation of myocardial dysfunction in stressed newborns

Cited by 29 publications

References 0 publications

The Regional Distribution and Determinants of Myocardial Blood Flow during Asphyxia in the Fetal Lamb

The Regional Distribution and Determinants of Myocardial Blood Flow during Asphyxia in the Fetal Lamb

Increased Regional Myocardial Blood Flows and Oxygen Deliveries during Hypoxemia in Lambs

Fetal Lamb Ventricles Respond Differently to Filling and Arterial Pressures and to in Utero Ventilation

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