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PubMed1994

[Late thrombolysis in acute myocardial infarct. Demonstration of myocardial tissue salvage by the assessment of pre- and post-thrombolytic perfusion and left ventricular function].

BACKGROUND: Pre and post treatment perfusion scintigraphy with Tc-99m-sestamibi is an accurate method to evaluate the effectiveness of thrombolytic therapy in patients with acute myocardial infarction. In the present study this method was used to verify whether thrombolytic therapy performed late (6 to 24 hours) after symptoms onset was still able to produce significant salvage of jeopardized myocardial tissue. METHODS: Fifteen patients (mean age 60.9 +/- 9 years) admitted to CCU 8-23 hours (mean 13.2 +/- 4 hours) after symptoms onset of their first acute myocardial infarction were studied. Both myocardial perfusion and left ventricular function were assessed before and after thrombolysis. Myocardial perfusion was studied using Tc-99m-sestamibi Single Photon Emission Tomography (SPET) before (pre-lysis SPET), 4.4 +/- 0.9 days (post-lysis SPET A) and 32 +/- 6 days (post-lysis SPET B) after thrombolysis. Uptake defects were graded from 0 to 4 using a 20-segment scheme. Regional ventricular function was evaluated using two-dimensional echocardiography before (pre-lysis ECHO), simultaneously with post-lysis SPET A (post-lysis ECHO A) and 32 +/- 4 days after treatment (post-lysis ECHO B); asynergy was graded from 1 to 4. Global left ventricular function was estimated using gated blood pool imaging and measuring the ejection fraction (EF) 5.3 +/- 1 (GBP 1) and 32 +/- 4 days after treatment (GBP 2). Within 6-9 days of admission all patients underwent coronary angiography. RESULTS: In pre-lysis SPET all patients had uptaken defects (score range 17-52, mean 34.6 +/- 12). According to the comparison between pre-lysis SPET and post-lysis SPET A, patients were divided into two groups: 7 patients with perfusion recovery (Group I) and 8 patients with absent or minimal perfusion recovery (Group II). In Group I the mean uptaken score decreased significantly (from pre-lysis SPET 34.2 +/- 12 to post-lysis SPET A 21.7 +/- 7, p < 0.05); in Group II the uptaken score remained unchanged (from pre-lysis SPET 34.8 +/- 12 to post-lysis SPET A 33.6 +/- 12, ns). In post-lysis SPET B both groups showed a defect reduction compared to post-lysis SPET A; however, the defect score of SPET B in Group I was significantly lower than that in Group II (18.7 +/- 16 vs 30.1 +/- 10, p < 0.05). The asynergic score in pre-lysis ECHO was the same in the two groups (19.5 +/- 4); in post-lysis ECHO A no significant decrease was observed in the two groups. In post-lysis ECHO B a significant decrease was seen in Group I (14.8 +/- 5, p < 0.05 vs pre-lysis ECHO and vs post-lysis ECHO A), but not in Group II (19.8 +/- 5, ns); the asynergic score in post-lysis ECHO B was significantly lower in Group I than in Group II (p < 0.05). In GBP 1 the EF was 38% +/- 6 in Group I and 40% +/- 6 in Group II (ns). In GBP 2 a significant increase was registered in Group I (47% +/- 10, p < 0.05), whereas in Group II the EF remained unchanged (40% +/- 6, ns). Coronary angiography showed a patent infarct related vessel in all Group I patients and in 2 Group II patients (p < 0.05). CONCLUSIONS: These results show that in patients with acute myocardial infarction treated with thrombolysis late after symptoms onset it is still possible to obtain an effective reperfusion and the consequent salvage of jeopardized tissue, as demonstrated by the recovery of both regional and global left ventricular function.

Aged↗
PubMed2006

Evaluation of left ventricular function using Tei index in patients with preinfarction angina.

OBJECTIVE: The study investigated whether preinfarction angina influences left ventricular functions assessed using Tei index, which is an independent predictor for left ventricular dysfunction in acute myocardial infarction. METHODS: We studied 96 patients with acute myocardial infarction with ST segment elevation (80 men, 16 women; mean age 57.5+/-9.9 years) who were assigned into 2 groups: with and without preinfarction angina. All patients were serially evaluated by 2-dimensional and Doppler echocardiography on the days 1, 6, and 30, and were followed up for 30 days for incidence of complications. RESULTS: We observed that Tei index was lower on the days 1, 6 and 30 (0.49+/-0.20 vs. 0.59+/-0.20, p=0.003, 0.46+/-0.20 vs. 0.56+/-0.20, p=0.001, 0.44+/-0.20 vs. 0.53+/-0.10, p=0.01) in patients with preinfarction angina as compared with those without angina. Tei index significantly decreased during follow-up (0.49+/-0.20, 0.46+/-0.20, 0.44+/-0.20; p=0.02) in patients with preinfarction angina, while it did not change significantly in patients without preinfarction angina (p=0.2). Echocardiographically significant improvements were observed in E deceleration time, isovolumic relaxation time and ejection time in all patients, whereas significant improvements in ejection fraction, wall motion score index and isovolumic contraction time were observed only in patients with preinfarction angina during follow-up. Mortality, Killip class >or=2, pericarditis, atrial fibrillation, and left ventricular thrombus were lower in patients with preinfarction angina. CONCLUSION: These data indicated that the patients with preinfarction angina had better preserved systolic left ventricular function and Tei index values. Also, it was observed that preinfarction angina may cause earlier and more prominent myocardial functional recovery and confer protection against complications on short-term after first acute myocardial infarction.

Angina, Unstable↗
PubMed1991

[Angiocardiographic evaluation of the left ventricular function in adult and pediatric subjects with interatrial defect of the ostium secundum type].

In order to assess left ventricular function in adults and children with ostium secundum atrial septal defect (ASD), 42 patients were examined by hemodynamic and angiocardiographic techniques. Patients were divided into three groups: Group I, 18 patients (mean age 42 years) with ASD; Group II, 14 patients (mean age 9 years) with ASD; Group III, 10 patients without cardiopathies who represented the control group. The following parameters of ventricular function were assessed: left ventricular end diastolic volume, global and regional left ventricular ejection fraction, left ventricular telediastolic pressure, mean pulmonary artery pressure, the ratio between pulmonary flow and systemic flow (QP/QS). Group I patients showed higher values of left ventricular end diastolic pressure and mean pulmonary artery pressure (16 +/- 0.6 mmHg; 33 +/- 1.5 mmHg) in relation to those of Group II (5.1 +/- 0.4 mmHg; 14 +/- 1.4 mmHg) and Group III (8.1 +/- 0.5 mmHg; 18 +/- 1.6 mmHg). In both cases the difference was statistically significant (p less than 0.001). A significant difference (p less than 0.05) was also noted in the incidence of mitral valve prolapse between patients in Group I and II. There was no significant difference (p = NS) however, between overall ejection fraction values in the three groups of patients; a lower regional ejection fraction (postero-basal segment) was recorded in Group I patients with mitral valve prolapse in comparison to patients in the other two groups (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2003

[Mid- to long-term effects of delayed percutaneous coronary intervention on left ventricular function and prognosis in patients with acute myocardial infarction].

OBJECTIVE: To investigate the mid- to long-term effects of delayed percutaneous coronary intervention (PCI) on the left ventricular function and clinical outcome of patients with acute myocardial infarction (AMI). METHODS: PCI (including percutaneous transluminal coronary angioplasty and stenting) was performed in 42 patients within 1 to 2 weeks following the onset of AMI (PCI group), with another 31 patients who were admitted within the same period to receive medication for AMI serving as the control group. The patients in both groups were observed for comparison of the occurrence of reinfarction and angina, mortality at 1 and 6 months, and findings by ultrasound cardiograms (UCG). RESULTS: In PCI group, the left ventricular function were obviously improved as compared with the control group (P<0.01) 1 month after the onset of AMI, showing greater improvement at 6 months (P<0.01). No death or reinfarction occurred in the PCI group, with only 1 patients experiencing angina 5 months after PCI. In control group, death occurred in 2 cases, reinfarction in 1 case, recurrent angina in 4 cases (include 2 cases of early postinfarction angina). CONCLUSION: Delayed PCI may significantly improve the prognosis of patients with AMI and prolong their survival without cardiovascular accidents and ameliorate their left ventricular functions, with high success rate of the operation.

Adult↗
PubMed1995

Prospective study of left ventricular function after radiofrequency ablation of atrioventricular junction in patients with atrial fibrillation.

BACKGROUND: In patients with drug resistant incessant supraventricular tachycardia, radiofrequency induced ablation of the atrioventricular junction and pacemaker implantation have hitherto been considered a treatment of last resort. OBJECTIVE: To assess the short and long term effects of ablation of the atrioventricular junction on systolic and diastolic left ventricular function in patients with atrial fibrillation with and without impaired left ventricular function. PATIENTS: 29 patients (19 men; mean age 65 (SD 7) years (range 50-76)) undergoing ablation of the atrioventricular junction for drug refractory atrial fibrillation were examined a mean of 2, 65, and 216 days after ablation of the bundle of His. MAIN OUTCOME MEASURES: Left ventricular ejection fraction and early filling deceleration times (Edec) were assessed by Doppler echocardiography after 1 to 2 hours of ventricular pacing at a rate of 80 beats/minute. RESULTS: In 14 patients with a left ventricular ejection fraction < 50% left ventricular ejection fraction increased significantly from 32% (11%) to 39% (11%) (65 days) and 45% (11%) (216 days) (P < 0.001); Edec increased from 142 (46) ms to 169 (57) ms (65 days) and 167 (56) ms (216 days) (P < 0.05). In 15 patients with an ejection fraction > or = 50% at the initial examination no significant change in systolic function was observed. CONCLUSIONS: In patients with left ventricular dysfunction long term improvement of systolic and diastolic left ventricular function was seen after ablation of the atrioventricular junction for rate control of atrial fibrillation. This procedure had no adverse effects on normal left ventricular function.

Aged↗
PubMed1971

Pressure-flow studies in man: effect of atrial systole on ventricular function in mitral stenosis.

The effect of atrial contraction on left ventricular function in six patients with varying degrees of mitral stenosis was determined by utilizing the pressure gradient technique to measure instantaneous aortic blood flow and pressure. Aortic flow was measured as ventricular rate was controlled by right ventricular pacing to create A-V (atrioventricular) dissociation at varying rates (90-150 beats/min). At each heart rate, beats with preceding P waves, effective atrial systole, were grouped according to the duration of the P-R interval. Beats without P waves served as controls. There was always a significant increase in stroke volume, created by effective atrial systole, but the P-R interval at which it took place was different for each patient. There was no difference in the stroke volume for beats preceded by P waves having a P-R interval within the range of 0.05-0.20 sec. These beats were grouped for each patient, subjected to regression analysis, and compared to control beats. The absolute and percent change created by effective atrial systole was inversely proportional to the severity of the disease as determined by mitral valve orifice size. Effective atrial systole plays less of a role in augmenting left ventricular function in patients with mitral stenosis than in patients with normal valves.

Adult↗
PubMed1991

[Rest ventricular function in left heart bypass].

During partial left heart bypass (LHBP), the flow delivered by an assist device is easy to measure while residual left ventricular function (LVI) seems difficult to assess. In this study, we have attempted to define the separate right and left ventricular function during LHBP. In 6 anesthetized dogs, following thoracotomy and systemic heparinization, aorta and left atrium were cannulated and connected to the servo-controlled roller pump (modified Stöckert-System). Following saline infusion (30 ml/kg), LHBP was started and maintained at 50 ml/min/kg throughout 6 h. Standard hemodynamic parameters were continuously monitored. Cardiac output, blood gas analyses, hemoglobin and activated coagulation time were measured at regular intervals. LVI was calculated as the difference between cardiac output and assist-flow rate. Other derived variables were obtained using standard formulas. The Wilcoxon rank-test was used for the statistical analysis. The results, as median and 25th-75th percentile, are summarized in the graphics 1-6. Under the experimental conditions of this study, the flow performance and stroke work of the right ventricle remained unchanged, while the work-unloaded left ventricle maintained only a part of systemic perfusion. Neglecting the physiological shunt and its changes, which influences the difference between the left and right ventricular output, the simple formula to assess LVI during LHBP seems plausible.

Animals↗
PubMed1997

Prediction of improvement of ventricular function after revascularization. 18F-fluorodeoxyglucose single-photon emission computed tomography vs low-dose dobutamine echocardiography.

AIMS: To compare assessment of myocardial flow and glucose metabolism by single-photon emission computed tomography (SPECT) with low-dose dobutamine echocardiography in predicting improvement in regional and global left ventricular function after coronary artery bypass grafting. METHODS AND RESULTS: Thirty patients with regional wall motion abnormalities (mean ejection fraction 32 +/- 19%) were studied with low-dose dobutamine echocardiography (5 and 10 micrograms. kg-1 min-1) and thallium-201/ 18F-fluorodeoxyglucose(FDG) SPECT prior to surgery. For comparative analysis, a 13-segment model was used. Postoperative improvement was predicted if the echocardiogram showed that wall motion abnormalities were reversible during the dobutamine infusion and there was normal perfusion or relatively increased FDG uptake in perfusion defects (mismatch) in dyssynergic segments on SPECT. After surgery, ventricular function was reassessed. An echocardiogram was taken at the 3 month follow-up with the patient at rest. Regional wall motion had improved in 62/168 (37%) revascularized segments. In predicting functional outcome, low-dose dobutamine echocardiography reached a sensitivity of 89% and a specificity of 82%, with a positive predictive value of 74% and a negative predictive value of 93%, whereas for thallium-201/FDG SPECT these values were 84%, 86%, 78% and 90%, respectively. In patients with more than two viable segments on either technique, the wall motion score index, a surrogate of global ventricular function, improved significantly. CONCLUSION: For the optimal prediction of functional outcome, combined assessment of flow and FDG imaging is needed. Both thallium-201/FDG SPECT and low-dose dobutamine echocardiography appear comparable and similarly accurate in predicting improvement of left ventricular function after surgical revascularization.

Analysis of Variance↗
PubMed1991

Study on the effects of six intravenous anesthetic agents on regional ventricular function in dogs (thiopental, etomidate, propofol, fentanyl, sufentanil, alfentanil).

This study evaluates the effects of 30 min increasing doses infusions of six intravenous anesthetic agents (thiopental, etomidate, propofol, fentanyl, sufentanil and alfentanil) on regional ventricular function in a normal and an acute ischemic heart segment in dogs. Part 1 discusses the methodology used in this experimental design with emphasis on the sensitivity and the limitations of the parameters used to assess ventricular performance and contractility. Part 2 reports the effects on regional and global ventricular function, which occur when one segment is made acutely ischemic. Part 3 reports and discusses the effects of increasing infusions of the three induction agents thiopental, etomidate and propofol on systemic and regional ventricular function. These agents induced a dose-dependent decrease in left ventricular end-systolic pressure. End-diastolic length also decreased in the normal and the acute ischemic segment for the three agents, indicating a decrease in left ventricular loading. This effect was most pronounced for propofol. At the doses tested, etomidate did not alter regional myocardial function significantly in any of the two segments. Thiopental, on the other hand was associated with a dose-dependent decrease in systolic shortening, that was significantly greater in the ischemic segment. This suggested that thiopental depresses myocardial function more in the acute ischemic heart than in the normal heart. Propofol decreased systolic shortening similarly in both segments. In part 4 the effects of the three narcotics fentanyl, sufentanil and alfentanil are reported. Fentanyl and sufentanil induced a dose-dependent decrease in heart rate. Left ventricular end-systolic pressure remained unchanged despite the increasing infusion rate. Fentanyl increased regional end-diastolic length and systolic shortening at the highest infusion rate. This phenomenon is not apparent for sufentanil, suggesting that different mechanisms are involved to compensate for the expected bradycardia-induced hypotension. Alfentanil did not alter systemic and regional hemodynamics significantly in this study design.

Alfentanil↗
PubMed1993

Propofol-fentanyl anaesthesia in cardiac surgery: a comparison in patients with good and impaired ventricular function.

The haemodynamic effects of propofol-fentanyl anaesthesia for elective cardiac surgery were compared in 24 patients with good left ventricular function (ejection fraction > 45%, left ventricular end-diastolic pressure < 16 mmHg) and nine patients with impaired function. Anaesthesia was induced with fentanyl 25 micrograms.kg-1 and pancuronium 0.1 mg.kg-1 and was maintained with a variable rate propofol infusion, mean rate 2.61 mg.kg-1 x h-1 in the good ventricular function group and 2.71 mg.kg-1 x h-1 in the impaired function group. Additional fentanyl 7.5 micrograms.kg-1 was given before sternotomy. Ventilation to normocarbia was with air and oxygen (FIO2 0.6). Haemodynamic measurements were made before induction, after tracheal intubation, before and after sternotomy and before aortic cannulation. There were no significant differences between the groups in any haemodynamic variables during the study. Twenty minutes after intubation both groups showed a decrease from pre-induction values in mean arterial pressure (p < 0.05) and left ventricular stroke work index (p < 0.05), the reduction in left ventricular stroke work index remaining significant during the prebypass period in both groups. There were no significant changes in right or left sided filling pressures, systemic vascular resistance or heart rate. The technique decreased cardiac work and effectively controlled the autonomic responses to sternotomy in both groups. This study suggests that propofol may be a suitable adjunct to opioid anaesthesia in patients with impaired ventricular function having cardiac surgery.

Adolescent↗
PubMed1983

Effect of age on left ventricular function during exercise in patients with coronary artery disease.

The purpose of this study was to assess the effect of age on left ventricular performance during exercise in 79 patients with coronary artery disease (greater than or equal to 50% narrowing of one or more major coronary arteries). Fifty patients under the age of 60 years (group I) and 29 patients 60 years or older (group II) were studied. Radionuclide angiograms were obtained at rest and during symptom-limited upright bicycle exercise. The history of hypertension, angina or Q wave myocardial infarction was similar in both groups. Multivessel coronary artery disease was present in 30 patients (60%) in group I and in 19 patients (66%) in group II (p = not significant). There were no significant differences between the two groups in the hemodynamic variables (at rest or during exercise) of left ventricular ejection fraction, end-diastolic volume, end-systolic volume and cardiac index. Exercise tolerance was higher in group I than in group II (7.8 +/- 0.4 versus 5.7 +/- 0.4 minutes, p = 0.009), although the exercise heart rate and rate-pressure product were not significantly different between the groups. There was poor correlation between age and ejection fraction, end-diastolic volume and end-systolic volume at rest and during exercise. Abnormal left ventricular function at rest or an abnormal response to exercise was noted in 42 patients (84%) in group I and in 25 patients (86%) in group II (p = not significant). Thus, in patients with coronary artery disease, age does not influence left ventricular function at rest or response to exercise. Older patients with coronary artery disease show changes in left ventricular function similar to those in younger patients with corresponding severity of coronary artery disease.

Adult↗
PubMed1983

Effect of oral disopyramide therapy on left ventricular function.

To study the effect of oral disopyramide therapy on left ventricular function, a subject of some controversy, we obtained first-pass radionuclide ventriculograms with a multicrystal gamma camera in 19 patients with or without therapy. Our findings demonstrated that disopyramide causes deterioration in left ventricular function in patients with abnormal ejection fractions. This effect is rarely recognized clinically and occurs despite safe therapeutic serum levels.

Administration, Oral↗
PubMed1987

Determinants of improved left ventricular function after thrombolytic therapy in acute myocardial infarction.

Many studies have been performed to evaluate the efficacy of thrombolytic therapy in achieving reperfusion, salvaging myocardium and enhancing survival. This review discusses the concordance between the results of these clinical studies and the observations made in experimental animals of the effect of reperfusion on the recovery of left ventricular function. The evaluation of functional recovery is affected by the timing of the measurement and the sensitivity of the method for detecting regional abnormalities. In addition, the underlying coronary anatomy also determines outcome, so that infarct location, collateral circulation and the degree of coronary obstruction merit consideration. Two factors are of paramount importance in determining the amount of myocardium salvaged, the recovery of left ventricular function and the reduction in mortality. These factors are: the time delay until reperfusion is achieved and the adequacy of the coronary reflow. The close agreement between studies measuring the effect of reperfusion on left ventricular function and studies with mortality as the end point provides indirect evidence that enhancement of survival in patients treated with thrombolytic agents is mediated by recovery of ventricular function.

Angioplasty, Balloon↗
PubMed1994

Effects of norepinephrine on right ventricular function in septic shock patients.

OBJECTIVE: To study the effects of norepinephrine on right ventricular function in patients with hyperdynamic septic shock. DESIGN: Prospective, open study. SETTING: A 15 bed ICU in a university hospital. PATIENTS: 9 patients with hyperdynamic septic shock (SBP < 90 mmHg, Cl > or = 4 l.min-1.m-2, SVRI < or = 850 dynes.s.cm-5m-2 and oliguria). INTERVENTIONS: Plasma volume expansion was used to correct a suspected volume deficit and then, norepinephrine infusion was started and titrated to restore systemic blood pressure to the normal range (mean infusion rate: 1.1 +/- 0.2 mcg.kg-1.min-1). Norepinephrine was the only vasoactive agent used in these patients. MEASUREMENTS AND RESULTS: A modified Swan-Ganz catheter mounted with a fast response thermistor was inserted in each patient, allowing repeated measurements of RVEDVI and RVEF. At time of inclusion to the study, all but one patient had elevated MPAP (23 +/- 4 mmHg) and RVEF < or = 50%, and all patients had RVEDVI > or = 90 ml.m-2. During norepinephrine infusion, MAP increased from 51 +/- 9 to 89 +/- 10 mmHg (p < 0.0001), PVRI increased from 204 +/- 35 to 286 +/- 63 dynes.s.cm-5.m-2 (p < 0.05), and despite this increase in right ventricular afterload, no detrimental effect in RVEF (36 +/- 11 to 36 +/- 10%) or in RVEDVI (116 +/- 30 to 127 +/- 40 ml.m-2) was observed. A Frank-Starling relationship for the right ventricle was constructed by plotting an index of ventricular performance (RVSWI) against an index of ventricular preload (RVEDVI). A significant upward shift to the right of the relationship was observed during norepinephrine infusion. CONCLUSION: It was concluded that norepinephrine exerted a favourable effect on right ventricular function.

Adult↗
PubMed1993

Clinical course and left ventricular function in patients with acute myocardial infarction following delayed recanalization of infarct-related artery.

The effect of delayed recanalisation of the infarct related artery on clinical course and left ventricular functions was studied in 23 patients with acute myocardial infarction (Group 2). Another 82 patients with acute myocardial infarction served as controls: 48 patients with immediate recanalisation of the infarct related artery following intracoronary thrombolytic therapy (Group 1) and 34 patients with unsuccessful thrombolysis with the artery remaining occluded on repeat angiography (Group 3). Baseline clinical characteristics and left ventricular ejection fractions in the three groups did not differ statistically. Following intracoronary thrombolysis the clinical features and left ventricular functions in the three groups, respectively were as follows: post infarction angina--45.8%, 13.1% and 11.8% (1 vs. 2 and 3, P < 0.05); reinfarction--29.2%, 8.7% and 11.8% (1 vs. 2 and 3, P < 0.05); mortality--0%, 0% and 11.8% (1 and 2 vs. 3; P < 0.05); aneurysm--16.7%, 21.7% and 52.9% (1 and 2 vs. 3, P < 0.05); heart failure--20.8%, 21.7% and 47.1% (1 and 2 vs. 3, P < 0.05). Left ventricular ejection fractions on the second and on days 10-14 were, respectively, 47.6 +/- 1.1%, 42.8 +/- 1.1% and 39.2 +/- 1.6% (1 vs. 2 and 3, P < 0.05) and --52.1 +/- 1.0%, 48.9 +/- 1.1% and 44.3 +/- 1.5% (1 and 2 vs. 3, P < 0.05). Thus following delayed recanalisation of the infarct related artery the clinical course and left ventricular function improved significantly in comparison to patients without recanalisation.

Adult↗
PubMed1983

Amsacrine cardiotoxicity: assessment of ventricular function by radionuclide angiography.

Serial assessment of ventricular function by means of a nuclear medicine technique was performed in six patients with malignant disease receiving chemotherapy with amsacrine. Two patients who received treatment long enough so that greater than 580 mg/m2 of the drug was administered showed a significant decrease in left ventricular ejection fraction. Four patients who received total doses of 325-510 mg/m2 of amsacrine did not experience significant change in their cardiac function.

Aged↗
PubMed1993

Ventricular function after normothermic versus hypothermic cardioplegia.

Warm cardioplegia produced by essentially continuous infusion has been used as an alternative to traditional cold intermittent infusion techniques during cardiac surgery, but its effects on postoperative left ventricular function have not been defined. We performed a randomized clinical trial to assess the effects of warm and cold blood cardioplegia on load-independent indices of ventricular function. Fifty-three patients were randomized to warm (n = 27) or cold (n = 26) cardioplegia. Myocardial oxygen consumption, lactate production, adenine nucleotides, and adenine nucleotide degradation products were measured during cardioplegia and reperfusion. In 13 patients per group, pressure-volume loops were constructed and ventricular function was assessed 3 hours after the operation. Warm cardioplegia resulted in greater myocardial lactate production but improved recovery of oxygen consumption during reperfusion. Depletion of adenosine triphosphate was similar between groups, but total adenine nucleotides (adenosine triphosphate + adenosine diphosphate + adenosine monophosphate) fell further during warm cardioplegia. Cold cardioplegia was associated with an accumulation of adenosine diphosphate and adenosine monophosphate. Creatine kinase MB isoenzyme release was reduced in the warm group. Three hours after the operation, end-systolic elastance and preload-recruitable stroke work index were increased after warm cardioplegia, and early diastolic relaxation was also increased. Increased systolic function after warm cardioplegia may have been related to improved myocardial protection, elevated arterial lactate concentrations, or increased circulating catecholamine levels. Altered diastolic compliance in the warm group may reflect greater active relaxation during early diastolic filling.

Adenine Nucleotides↗
PubMed1977

Echocardiographic assessment of left ventricular function. Investigation of infants, children and teenagers without heart disease.

Echocardiography was used to study left ventricular function in 75 infants, children and teenagers without heart disease. Normal values for echocardiographic parameters of left ventricular contractility were obtained and are presented in Tables. Systolic time intervals were measured from aortic cusp echoes and the normal range and correlation to heart rate and age are given. Computer analyses of echocardiograms from the left ventricle and the anterior mitral leaflet were done and normal values for the instantaneous velocities thus derived are given. To test the normal variation of left ventricular function with time 12 children were examined repeatedly during 1 wk. 95% tolerance limits for the variation of the different functional parameters are given. To test the reproducibility of the echocardiographic measurements 11 children with various forms of heart disease were examined consecutively by two different observers and the 95% tolerance limits for the difference between measurements were calculated.

Adolescent↗