Clinical results of left ventricular free wall rupture following acute myocardial infarction

We studied 19 cases of Left Ventricular Free Wall Rupture (LVFWR) following acute myocardial infarction, admitted to our CCU between 1987 and 1996. We were able to treat 15 patients and diagnosed 4 cases as LVFWR at postmortem after sudden deaths. Of the treated 15 patients, 11 survived: 1 out of 2 repaired under cardiopulmonary bypass (CPB), 5 out of 7 repaired without CPB, and 5 out of 6 non-surgically treated. Although the survival rate for those able to be treated was 73%, overall rate was 58%. There were 7 cases of blow-out type: 4 of which were sudden deaths, and 3 were operated. Thoracotomy and direct closure of rupture without CPB was done at bed-side in 2 cases. Even though hemostasis was successful, they did not survive. The 3rd case survived with the patch closure under CPB. In this case, the circulation was maintained pre-operatively with the pericardial-central venous bypass drainage method. This method seems to be extremely effective in saving blow-out cases. There were 12 subacute patients. Although 2 cases were lost, total of 10 patients were saved, including 2 direct suture closures of rupture without CPB, 3 median sternotomy and fibrin-glue fixations, 1 where only pericardial drainage was done, and 4 in whom percutaneous intrapericardial fibrin-glue fixation therapy was utilized. Since the risk of secondary damage to the fragile infarcted are from direct suturing of ruptured myocardium exists in LVFWR, we changed to the Infarction Exclusion Technique under CPB during surgical repair, based on our experiences with ruptured intraventricular septum. In general, the only treatment believed to be available for LVFWR has been surgical. However, our experiences suggest that other treatments may also be effective. If the best suitable method could be chosen from various therapies, it may contribute to improving outcome statistics. The reduction of left ventricular pressure in the treatment is extremely important, being the key to improving survival rate.     

Ventricular interdependence: significant left ventricular contributions to right ventricular systolic function

This article reviews diastolic and systolic ventricular interaction, and clinical pathophysiological conditions involving ventricular interaction. Diastolic ventricular interdependence is present on a moment-to-moment, beat-to-beat basis, and the interactions are large enough to be of physiological and pathophysiological importance. Although always present, ventricular interdependence is most apparent with sudden postural and respiratory changes in ventricular volume. Left ventricular function significantly affects right ventricular systolic function. Experimental studies have shown that about 20% to 40% of the right ventricular systolic pressure and volume outflow result from left ventricular contraction. This dependency of the right ventricle on the left ventricle helps to explain the right ventricular response to volume overload, pressure overload, and myocardial ischemia. The septum and its position are not the sole mechanism for ventricular interdependence. Ventricular interdependence causes overall ventricular deformation, and is probably best explained by the balance of forces at the interventricular sulcus, the material properties, and cardiac dimensions.     

Pseudoaneurysm of the left ventricle following repair for ventricular septal perforation

The patient was a 64-year-old man who was treated surgically for an infarct-related ventricular septal perforation. Pseudoaneurysm of the left ventricle was recognized on the 38th postoperative day. Emergency surgery was performed. It seemed that insufficient resection of the infarcted myocardium was performed during the initial surgery to avoid narrowing the ventricular dimension by direct closure of the left ventricle, but this resulted in pseudoaneurysm of the left ventricle. Left ventricular free wall plasty with a patch should be performed during the initial surgery.     

Can indices of left ventricular function be applied to the right ventricle?

This article compares conventional indices of contractile function in the right and left ventricles. The low operating pressures and left ventricles. The low operating pressures and complex geometry complicate evaluation of right ventricular function. However, when the characteristics of its vascular load are taken into account, the complex right ventricular chamber has pump properties that are similar to the high pressure left ventricular chamber.     

Comparison of left and right ventricular function in acute myocardial infarction

Pulmonary arterial end-diastolic and mean right atrial pressures were compared in 25 patients with acute myocardial infarction and in one patient with unstable angina. No consistent relationship was observed between these pressures. Simultaneous ventricular function curves relating the stroke work of each ventricle to its respective filling pressure were constructed on 34 occasions, dextran infusion or diuresis being used to alter the filling pressure. The curves from each ventricle were described mathematically by a quadratic (parabolic) function as well as by a straight line function and then compared by canonical correlation analysis. Alterations in the left ventricular function curves occurred with and without depression or right ventricular function curves. These hemodynamic measurements demonstrate that acute myocardial infarction can alter the relationship between left and right ventricular function.     

Differential alterations in left and right ventricular G-proteins in congestive heart failure due to myocardial infarction

In order to examine the status of G-proteins in congestive heart failure due to myocardial infarction, the left coronary artery in rats was ligated and animals assessed after 4, 8 and 16 weeks. Sham-operated control and experimental animals were used for the preparation of membranes from the viable (uninfarcted) left and right ventricles. Adenylyl cyclase activities in the presence of pertussis toxin and cholera toxin were increased and decreased in left ventricles from all groups, respectively. On the other hand, adenylyl cyclase activities in 8 and 16-week experimental right ventricles were unaltered in the presence of pertussis toxin and increased in the presence of cholera toxin. Depression of adenylyl cyclase activities in left ventricles from all groups as well as in the right ventricle at 4 weeks were not evident when enzyme activity was determined in the pertussis toxin-treated membranes in the absence or presence of Gpp(NH)p. Cholera toxin-catalyzed ADP ribosylation was decreased in left ventricles from all infarcted groups and increased in the right ventricles at 8 and 16 weeks whereas the pertussis toxin-catalyzed ADP ribosylation was increased in all experimental tissues except in the right ventricles at 8 and 16 weeks. G(s alpha)-protein content was decreased in the left ventricle at 16 weeks and increased in the right ventricles at 8 and 16 weeks of myocardial infarction. On the other hand, G(i alpha)-protein content was increased in left ventricles from all infarcted groups and the 4-week right ventricle but was unaltered in 8 and 16-week right ventricles. An increase in mRNA abundance for G(i alpha)-protein was seen in both left and right ventricles following myocardial infarction. A significant increase in mRNA level for G(s alpha)-protein was observed in all left ventricles and 8-week right ventricle following the coronary occlusion. These results suggest that changes in Gs- and Gi-proteins in the failing heart due to myocardial infarction are chamber-specific and are dependent upon the stage of congestive heart failure.     

Left ventricular regional systolic motion in patients with right ventricular pressure overload

The highly reactive and cytotoxic hydroxyl radical (OH) was found by electrochemical detection to be produced in reactions involving hydrogen peroxide (H2O2) and the nitric oxide (NO) donor diethylamine- NO complex. Using aromatic hydroxylation of salicylate as a specific indicator of OH, three salicylate hydroxylation products were identified; catechol, 2,3- and 2,5-dihydroxybenzoic acid. Four additional compounds were detected but not identified. The interactions of H2O2 and NO represent a biologically feasible reaction mechanism that can account for OH-induced damage in cellular environments where transition metal ions are unavailable for participation in the superoxide-mediated Fenton reaction. The ability of the NO/H2O2 complex to generate OH independently of iron or other transition metals provides a new focus for studies concerned with the origin of tissue-specific damage caused by oxygen-derived species.     

Optimal control evaluation of left ventricular systolic dynamics

A model of the contracting left ventricle was developed, in which the left ventricle was represented as a time-varying compliance. The vascular load included the nonlinear (Bernoulli) resistance of the aortic valve, blood inertance, and a Windkessel model of the arterial tree. Owing to the obligatory aerobic nature of the heart, oxygen consumption can be used to characterize the energy utilized by the myocardium. An adaptive control law was developed for determining the systolic time course of ventricular pressure and volume that minimizes cardiac oxygen consumption. Three main determinants of myocardial oxygen consumption were included in the integral criterion function: developed wall tension, inotropic state, and external (mechanical) work. The optimal control problem was solved using the Pontryagin maximum principle. The model could predict, in good agreement with experimentally obtained data, systolic time course of ventricular pressure and volume, as well as directional changes in the duration of isovolumic contraction and ejection phase under various conditions of end-diastolic volume, mean aortic pressure, and inotropic state.     

Doppler stress echocardiography of the left and right ventricle: a new echo device to quantify left ventricular backward failure

OBJECTIVES: A novel non-invasive procedure which evaluates left-right ventricular interaction is introduced. This procedure is suitable for the classification of congestive heart failure. METHODS: In 48 patients showing mild, moderate or advanced stage congestive heart failure (NYHA I-III) Doppler echocardiography was performed at rest, during and after submaximal bicycle exercise. Mitral (m) and tricuspid (t) filling parameters were determined: early diastolic (VEm, VEt) and atrial maximal velocities (VAm, VAt), the velocity integrals (Em, Et, Am, At) and the corresponding ratios (VE/VAm, VE/VAt, E/Am, E/At). Group 1 (n = 29) was composed of those patients presenting with a VE/VAm < 1 at rest. Four individuals (group 2) were found to have a VE/VAm ratio < 1 during exercise only. Six other patients showing a dilated left ventricle or an ejection fraction of less than 40% produced false negative results in left ventricular Doppler examination (VE/VAm > 1) at rest and during exercise (group 3). In 9 cases (group 4) systolic function, size and Doppler echocardiographic parameters of the left ventricle were proven to be normal. RESULTS: The VE/VAt-ratio decreased notably during exercise (p < 0.05) but increased again after exercise in group 3. In the groups 1 and 2 similar changes occurred as well, however not to a significant degree. In group 4, exercise VE/VAt ratio did not differ from values seen at rest or during recovery (variability 4%). CONCLUSION: The results of this study indicate, that high sensitivity towards left ventricular backward failure can be achieved for Doppler stress echocardiography by extending the examination to right-sided diastolic parameters.     

Impaired regional fatty acid uptake and systolic dysfunction in hypertrophied right ventricle

Little information is available regarding the determinants of systolic contractile function of the hypertrophied right ventricle (RV). The purpose of this study was to clarify the relationship between myocardial metabolism and contractile function in the hypertrophied RV due to pulmonary hypertension (PH). METHODS: Iodine-123-labeled 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) and 99mTc-sestamibi (MIBI) SPECT were performed to calculate the RV-to-left ventricle (LV) tracer uptake ratio (RV/LV) in 21 patients with PH (6 with primary PH and 15 with chronic thromboembolic PH). The patients also underwent electron-beam CT to assess RV ejection function (RVEF) and percentage systolic wall thickening (%SWT) and right heart catheterization to measure mean pulmonary arterial pressure (mPAP). RESULTS: There were significant positive correlations between mPAP and MIBI-RV/LV (r = 0.89, p < 0.001) and between mPAP and BMIPP-RV/LV (r = 0.86, p < 0.001). However, 8 patients showed lower BMIPP-RV/LV than MIBI-RV/LV, indicating the impairment of myocardial fatty acid uptake in the RV. These patients had lower RVEF and %SWT compared to those with normal myocardial fatty acid uptake (RVEF = 28% +/- 10% compared to 40% +/- 9% and %SWT = 33% +/- 27% compared to 74% +/- 30%, respectively; p < 0.05 for both comparisons). Although mPAP did not differ between the groups, the RVEF-mPAP and %SWT-mPAP regression lines drawn from the patients with impaired myocardial fatty acid uptake were located below the lines from the patients with normal myocardial fatty acid uptake, suggesting disproportionately decreased RV myocardial contractility for a given mPAP in patients with impaired myocardial fatty acid uptake. The patients with the impaired fatty acid uptake in the RV had a significantly higher death rate (log-rank test, p < 0.05). CONCLUSION: The results from this preliminary study suggest that myocardial fatty acid uptake is impaired in the failing hypertrophied RV due to PH.     

Influence of right ventricular stimulation site on left ventricular function in atrial synchronous ventricular pacing

Septic shock is a dangerous condition with high mortality rates. In sepsis, the inducible form of nitric oxide (NO) synthase is induced, releasing high amounts of NO. Glucocorticoids have potent anti-inflammatory properties and are very effective in inhibiting the induction of this enzyme if administered before the shock onset. It is known that glucocorticoid receptor (GR) has critical cysteine residues for steroid binding in its hormone-binding and DNA-binding domains. It has also been reported that NO reacts with ---SH groups, forming S-nitrosothiols. Therefore, we examined the potential effect of NO on the ligand-binding ability of GR. NO donors (S-nitroso-acetyl-DL-penicillamine, S-nitroso-DL-penicillamine, or S-nitroso-glutathione) decreased, in a time- and dose-dependent manner, the binding of [3H]triamcinolone to immunoprecipitated GR from mouse L929 fibroblasts. The nonnitrosylated parent molecules, N-acetyl-DL-penicillamine, and reduced gluthatione were without effect. Scatchard plots revealed that the number of ligand binding sites and Kd were reduced (50%) by NO donors. Western blot analysis ruled out the possibility that dissociation of GR/heat shock protein 90 heterocomplex or decrease in GR protein would account for the inhibitory effect of NO. Decreased ligand binding to GR was found when NO donors were incubated with intact fibroblasts. Incubation with NO donors also decreased the steroid-induced reduction in [3H]uridine incorporation into RNA. All of these NO effects were inhibited by the thiol-protecting agent dithiothreitol. Therefore, S-nitrosylation of critical ---SH groups in GR by NO with consequent decreases in binding and affinity may be the mechanisms which explain the failure of glucocorticoids to exert their anti-inflammatory effects in septic shock.     

Long-term effect of inducible silent ischaemia on left ventricular systolic function

A new method of thin section preparation of III-V semiconductors and multilayers for transmission electron microscopy (TEM) is presented that exhibits considerable advantages over conventional methods such as ion beam milling and jet thinning. GaAs thin films and multilayers of GaAs/In chi Ga1-chi As/GaAs are grown over an etch release layer of AlAs on GaAs substrates by molecular beam epitaxy (MBE). Planar TEM sections prepared by selective etching from these samples show improved ability to image film morphology and dislocation arrangements, and the resulting large thin electron transparent areas facilitate dislocation density measurements and detection of spatial variations. Avoidance of radiation effects and wedge shaping, both common to ion milled samples, allows this method to be used to prepare uniform thickness standards of single layer GaAs films for EDS analysis or lattice imaging.     

Successful outcome of a left ventricular free wall rupture in a community hospital: case report

Rupture of the myocardium in the setting of acute myocardial infarction has a universally grim prognosis. The time that elapses between diagnosis and definitive therapy is the most critical determinant of the patient's outcome when death is not instantaneous. Survivors of this catastrophic event have not been frequently reported. We present a case of free wall left ventricular rupture in a patient with an acute myocardial infarction hospitalized in the Cardiac Care Unit of a small community hospital. The patient was successfully transferred to the referral institution for surgery. Rapid diagnosis, primary bedside therapy, and utilization of new surgical techniques helped obtain a good outcome.     

Performance of the lift ventricle in left ventricular obstructive cardiomyopathy

Whether volume expansion influences NaC1 reabsorption by the diluting segment of the nephron remains a matter of controversy. In the present studies this question has been examined in normal unanesthetized dogs, undergoing maximal water diuresis. Free water clearance (CH2O/GFR) has been used as the index of NaC1 reabsorption in the diluting segment. Three expressions have been employed for "distal delivery" of NaC1: a) V/GFR, designated as the "volume term"; b) (CNa/GFR + CH2O/GFR), the "sodium term;" and c) (CC1/GFR + CH2O/GFR), the "chloride term". The validity of these terms is discussed. Three techniques were used to increase distal delivery: 1) the administration of acetazolamide to dogs in which extracellular fluid (ECF) volume was not expanded (grop 1); 2) "moderate" volume expansion (group 2); and 3) "marked" volume expansion (group 3). CH2O/GFR increased progressively with rising values for "distal delivery" regardless of which term was used to calculate the latter. With all three delivery terms, differences in distal NaC1 reabsorption emerged between the two volume-expanded groups, though only with the "chloride" term did substantial differences also emerge between the nonexpanded group 1 dogs and both volume-expanded groups. In group 1, values for CH2O/GFR increased in close to a linear fashion up to distal delivery values equal to 24% of the volume of glomerular filtrate. However, at high rates of distal delivery the rate of rise of CH2O/GFR was less in group 2 than in group 1 and the depression of values was even greater in group 3. Within the limits of the techniques used, the data suggest that volume expansion inhibits fractional NaC1 reabsorption in the diluting segment of the nephron in a dose-related fashion. The "chloride" term was found to be superior to the "volume" and "sodium" terms in revealing these changes.     

Ablation of manifest left free wall accessory pathways with polarity reversal mapping: ventricular approach

Polarity reversal mapping for localization of the left free wall accessory pathway (AP) at the atrial insertion site has been shown to be effective for successful ablation, but this technique requires atrial septal puncture. We evaluated the safety, efficacy, and reproducibility of two dimensional polarity reversal mapping at the ventricular insertion site of the accessory pathway without atrial septal puncture in symptomatic patients with manifested left free wall AP. Polarity reversal mapping under the mitral annulus by transaortic approach was performed in 10 consecutive patients with conventional ablation catheter (6 French, 4 mm tip, 2 mm interelectrode distance), during sinus rhythm or atrial pacing. A low set high, bandpass filter (0.005-400Hz) was used. Radiofrequency (RF) ablation was performed at the site of ventricular electrocardiogram polarity reversal during sinus rhythm. Polarity reversal was identified in all patients at the ventricular side of the mitral annulus. Ablation was successful in all patients without complications. The procedure time was 86.0 +/- 21.1 min, the fluoroscopic exposure time was 16 +/- 12 min, the number of RF applications was 8 +/- 6, the power level 21 +/- 7 watts, and the time to initial AP block was 3.0 +/- 0.9 sec. Polarity reversal mapping is a safe and efficient technique at the ventricular insertion site. This technique might be complementary to the currently-utilized activation mapping technique.     

Resolution of late potentials with improvement in left ventricular systolic function in patients with first acute myocardial infarction

BACKGROUND: Little has been written about the use of computed tomography (CT) in the evaluation of small bowel obstruction (SBO) in children. The purpose of this study is to review the CT findings of SBO in a pediatric series and to increase awareness of CT as potential problem-solving tool for SBO in children. METHODS: The medical, surgical, radiographic, and CT scan records of 20 consecutive children with surgically proven SBO were retrospectively reviewed. Duodenal and neonatal obstruction was excluded. CT scans were evaluated for small and large bowel caliber, bowel wall thickening, the appearance of the mesentery, extraluminal abnormalities, and the ability to detect the cause of obstruction. RESULTS: Causes of obstruction included adhesions (nine), small bowel intussusception (four), abscess (two), segmental volvulus (two), Crohn disease (one), focal stricture (one), and internal hernia (one). Small bowel dilatation was present in 19/20 children. Small bowel caliber transition was noted in 17/19 children. Two children with no small bowel caliber transition had a collapsed colon. The colon appeared normal in caliber in nine children, collapsed in nine, and filled with stool proximally and collapsed distally in two. Small bowel thickening was present in six children and mesenteric venous engorgement in three. Specific causes of obstruction were identified on CT in nine children (45%) and could be correctly predicted in seven of nine children with adhesions. In four children, the causes were either not evident or alternate diagnoses could be made. CONCLUSION: CT can be a useful adjunct in evaluating the presence or causes of SBO in children.     

Echocardiographic findings in left ventricular to right atrial shunts

The echocardiographic abnormalities of tricuspid valve motion in 2 patients with left ventricular to right atrial shunts are described. In both patients the abnormal anatomy was defined at surgery, in one patient the shunt being above the tricuspid valve leaflets (supravalvar) and in the other patient through the septal leaflet (intravalvar). Different patterns of tricuspid valve systolic fluttering were seen in these two cases and the possible reasons for this are discussed. After surgical closure of the defects the systolic fluttering of the tricuspid valve was no longer observed. Echocardiography appears to be useful in detecting the presence of left ventricular to right atrial shunts which otherwise may be difficult to diagnose.     

Left ventricular free wall rupture as the presenting manifestation of acute myocardial infarction in diabetic patients

We present 5 diabetic patients with acute myocardial infarction in whom left ventricular free wall rupture was the presenting manifestation. Echocardiography may be indicated in diabetic patients with acute myocardial infarction and in shock, prior to thrombolysis.     

Effect of acute alterations in afterload on left ventricular function in patients with combined coronary artery and peripheral vascular disease

The GTP analog guanylylmethylene diphosphonate (GppCH2p) strongly inhibited polyuridylic acid-directed polypeptide synthesis in a cell-free translation system prepared from Agrobacterium tumefaciens. Fusidic acid increased even further the inhibitory action. The pre-translocational ribosomal complexes formed with the GppCH2p and the elongation factor G protected the ribosome against the depurinating action of crotin 2 assayed as the acid-dependent release of the RNA fragment whose terminal sequence is 5'-GAGGACCGGGAUGGAC-3'. The results allowed to conclude that the interaction of both crotin 2 and the elongation factor G with the A. tumefaciens ribosomes in the pre-translocational state must take place at overlapping, either sterically or allosterically, ribosomal sites which are equally accessible to the RIP.