Energy stores and metabolites in chronic reversibly and irreversibly dysfunctional myocardium in humans.

OBJECTIVES: Our goal was to study metabolic energy stores and lactate content in chronic reversibly and irreversibly dysfunctional myocardium. BACKGROUND: It is unknown whether metabolism is deranged in chronic reversibly and irreversibly dysfunctional myocardium in humans. Semiquantitative histological examinations have shown altered mitochondrial morphology and glycogen accumulation in dysfunctional regions. METHODS: We studied 25 patients with a mean ejection fraction of 38 +/- 9% scheduled for coronary artery bypass surgery. Regional perfusion and metabolism were assessed by positron emission tomography, and regional function was assessed by echocardiography. Perioperative myocardial biopsies were obtained from a control region and from a dysfunctional region. We analyzed biopsies for contents of noncollagen protein (NCP), ATP, ADP, AMP, glycogen and lactate. Six months after surgery we assessed wall motion by echocardiography to group patients in those with (n = 11) and without (n = 14) functional improvement. RESULTS: Reversibly dysfunctional myocardium had reduced perfusion (0.59 +/- 0.16 vs. 0.69 +/- 0.20 ml/g/min, p < 0.05), similar glucose-tracer uptake (92 +/- 12 and 95 +/- 14%), ATP/ADP ratio (2.4 +/- 1.1 and 2.4 +/- 0.7), glycogen content (631 +/- 174 and 632 +/- 148 nmol/microg NCP) and lactate levels (59 +/- 27 and 52 +/- 29 nmol/microg NCP) compared with control regions. Irreversibly dysfunctional regions (n = 14) had severely reduced perfusion (0.48 +/- 0.15 vs. 0.72 +/- 0.12 ml/g/min, p < 0.001) and glucose-tracer uptake (52 +/- 16 vs. 94 +/- 15%, p < 0.001), reduced ATP/ADP ratio (1.5 +/- 0.9 vs. 2.3 +/- 0.9, p < 0.05), similar glycogen content (579 +/- 265 vs. 593 +/- 127 nmol/microg NCP) and increased lactate levels (114 +/- 52 vs. 89 +/- 24 nmol/microg NCP, p < 0.01) compared with control regions. CONCLUSIONS: Contents of metabolic energy stores and lactate in chronic reversibly dysfunctional myocardium were preserved. In contrast, energy stores were depleted in myocardium without functional recovery after revascularization.

[Diagnosis of suspected thoracic aortic dissection. Focused on transesophageal echocardiography]. / Diagnostik ved mistaenkt torakal aortadissektion. Fokus på transøsofageal ekkokardiografi.

Over a five-year period (1990-1994), 72 consecutive patients were referred to transoesophageal echocardiography (TEE) on suspicion of thoracic aortic dissection. TEE was performed as the only or last investigation in 42 patients (58%). In 44 patients one or more other investigations were carried out before final clinical decision making: aortography (n = 30), X-ray computer tomography (CT, n = 18), and magnetic resonance imaging (MRI, n = 12). The final diagnosis was based on the combination of clinical information, the available examination results, and findings at surgery or autopsy; 31 of the patients were diagnosed as having aortic dissection. One patient with aortic dissection died during TEE while none of the other patients suffered major complications. The sensitivity (demonstration of dissection including correct classification in type A or B) was 81%, 80%, 45%, and 83% for TEE, aortography. CT, and MRI, respectively. The specificities were 88%, 93%, 71%, and 100%, respectively. Dissection of the thoracic aorta is a life-threatening condition demanding prompt and accurate diagnosis. None of the four techniques employed in the present study is ideal. Although TEE is adequate for immediate bedside examination our results show that more time-consuming and resource demanding investigations are sometimes required. Proper training and improved equipment may, however, increase the usefulness of TEE in patients with suspected aortic dissection.

Perivalvular cavities in endocarditis: abscesses versus pseudoaneurysms? A transesophageal Doppler echocardiographic study in 118 patients with endocarditis.

The appearance of perivalvular cavities (PCs) in patients with infectious endocarditis (IE) was studied by transesophageal echocardiography (TEE) color Doppler examinations to determine whether the color Doppler TEE presentation was in keeping with the current concept of PCs representing abscesses. Two heart centers participated in the study. Videotape recordings of TEE examinations in patients with IE were analyzed retrospectively for 18 months in both centers, and one center included patients prospectively for an additional 18 months. A total of 118 patients with a diagnosis of IE based on TEE and clinical and laboratory findings were seen during the study period. TEE showed PCs in 34 patients. In 3 patients who died, no autopsy was performed; the PCs were proved at autopsy or surgery in the remaining 31 patients, who constituted the study population. All PCs were echo free at TEE. Apart from one technically inadequate examination, all PCs contained color Doppler signals indicating intracavitary blood flow; the PCs communicated through a narrow channel with high-pressure regions (the left ventricle or the ascending aorta). At surgery or autopsy, only 2 of the 31 patients had pus accumulations besides the blood-filled PCs. At TEE the pus accumulations presented as echo-rich, shaggy tissue thickening. It is concluded that well-delineated, echo-free PCs with intracavitary color Doppler signals at TEE appear to be pseudoaneurysms, and therefore the term abscess should not be used in these cases. Although further studies are needed, our findings suggest that PCs more likely occur by infectious tissue weakening and subsequent dissection rather than as a result of primary abscess formation with secondary rupture.(ABSTRACT TRUNCATED AT 250 WORDS)

Thromboembolism in patients with advanced mitral valve prolapse.

Thromboembolism in mitral valve prolapse (MVP) has been suggested to occur in relation to valvular cul-de-sac recesses and endothelial wear-and-tear denudations. Such pathology would be suspected to be prominent in advanced cases of MVP necessitating open-heart operation. We therefore analysed the prevalence of perivalvular thrombi and episodes of systemic arterial embolism (SE) prior to operation in 21 consecutive patients with MVP and severe valve regurgitation. No perivalvular or left atrial thrombi were found during open-heart surgery, but three of the patients (14%, 3-36% with 95% confidence limits) experienced SE, in one case despite long-term anticoagulation. All cases of SE took place less than 3 months before operation. The results indicate that persistent thrombi are rare in MVP and severe valve regurgitation. However, such patients run a substantial risk of SE when they reach a clinical and haemodynamic stage that makes valve surgery mandatory.

Mitral annulus calcification and embolism.

Of 388 patients consecutively referred to echocardiography, 49 were suspected of having a cardiac source of systemic arterial embolism (SE). Mitral annulus calcification (MAC) was revealed in 27% of the patients with SE and in 8% of the remaining patients (p less than 0.05). The group of patients with SE were slightly older (median age 67 years) and included more female patients (47%) compared to the group without SE (62 years, p less than 0.05; 40% female patients, p greater than 0.05). However, the small differences in age and sex distribution did not explain satisfactorily the considerably increased prevalence of MAC in the group of patients with SE. Our preliminary data indicated that thromboembolism caused by left atrial dilatation and atrial fibrillation might be the most important cause of the condition in patients with MAC and SE. However, the significance of the possible mechanisms of embolism in patients with MAC and the incidence of the complication should be further clarified before therapy and prophylaxis can be suggested.

Clinically suspected severe ischaemia-induced mitral regurgitation. Spectrum of lesions and features of high surgical risk by echocardiography.

Eighteen patients with clinical signs suggesting severe mitral regurgitation secondary to ischaemic heart disease were assessed by echocardiography. Non-ischaemic diseases needing specific therapy were revealed in six patients. In the other 12 patients echocardiography demonstrated myocardial lesions explaining the mitral regurgitation. Apart from the distinction between non-ischaemic conditions and lesions induced by ischaemia, echocardiography seems to be helpful in the demonstration of severe yet operable mitral valve regurgitation due to a small ischaemic lesion. Such cases are opposed to functional mitral regurgitation caused by extensive myocardial injury as demonstrated by two-dimensional echocardiography and reflected by a minimum mitral valve/septum separation of more than 2 1/2 cm on the M-mode echocardiogram. These conditions make symptomatic improvement by mitral valve surgery unlikely and carry an extremely high operative mortality. A more precise definition by heart catheterization is required when serious clinical heart failure is not explained by the echocardiographic finding of severe global myocardial impairment.

Endomyocardial biopsy guided by cross-sectional echocardiography.

The usefulness of cross-sectional echocardiography during endomyocardial biopsy was examined in 10 consecutive patients with myocardial disease of undetermined origin. Twenty-eight endomyocardial biopsies were obtained from the left ventricle and 34 from the right ventricle. Echocardiography was performed simultaneously with monitoring of the biopsy procedure by means of fluoroscopy, pressure measurement, and electrocardiographic recording from the bioptome. Echocardiographic visualisation of the biopsy procedure was feasible in 100% of left and in 18% of right ventricular biopsies. Conventional positioning of the bioptome was corrected in a total of five cases because of inappropriate localisation as apparent from cross-sectional echocardiography. In the left ventricle the site of biopsy could be defined more precisely by echocardiography than by fluoroscopy. At the present stage of technical development the most important potential of ultrasonically guided endomyocardial biopsy seems to be the feasibility of obtaining selective biopsies from well defined areas of the left ventricle when serial analysis from a reproducible area is necessary.

Assessment of rheumatic mitral valve disease. Value of echocardiography in patients clinically suspected of predominant stenosis.

The value of echocardiography as compared with cardiac catheterisation was evaluated prospectively in 33 consecutive patients clinically suspected of predominant mitral stenosis. Patients with clinical signs of accompanying mitral regurgitation, no matter how severe, and patients with clinical findings indicating insignificant aortic valve disease were included. Critical mitral stenosis was defined by a valve area of less than or equal to 1 cm2. Severe mitral regurgitation was diagnosed by echocardiography on the basis of left ventricular dilatation (more than 3.2 cm/m2 at end-diastole) if not explained otherwise. Significant aortic valve disease was suspected in cases with aortic valve deformity and left ventricular dilatation or hypertrophy as defined by echocardiography. Mitral valve area by echocardiography correlated well with mitral valve area calculated from catheterisation data and a good interobserver correlation was found for echocardiographic measurement. Mitral stenosis, critical or non-critical, may mask significant coexistent valve lesions; echocardiography failed to discover severe mitral regurgitation requiring valve replacement in two patients with non-critical stenosis, and significant aortic regurgitation needing valve replacement was underestimated in one patient with critical mitral stenosis. A correct echocardiographic classification with respect to surgery, however, was obtained in: (1) all patients with clinically pure mitral stenosis (nine patients), and (2) all patients with combined mitral stenosis and regurgitation when either critical stenosis or severe regurgitation was found at echocardiography (12 patients). It thus appears that two out of three patients with mitral valve disease in whom the clinical findings indicate predominant stenosis can be correctly evaluated with the echocardiogram.

Non-invasive diagnosis in clinically suspected atrial septal defect of secundum or sinus venosus type. Value of combining chest x-ray, phonocardiography, and M-mode echocardiography.

Twenty-three consecutive patients with clinical (auscultatory and electrocardiographic) signs of uncomplicated atrial septal defect of secundum or sinus venosus type were examined by chest x-ray, phonocardiography, and echocardiography, before right heart catheterisation. Seventeen (74%) had atrial septal defect, two patients (9%) had insignificant pulmonary stenosis, and four subjects (17%) were normal. No false positive diagnosis of atrial septal defect was made by chest x-ray examination, whereas increased vascular markings were incorrectly interpreted as pulmonary congestion in one case. Four patients had x-ray films showing questionable signs of left-to-right shunt. Six of 15 patients with a large left-to-right shunt were correctly selected for surgery based on radiological findings. One false negative but no false positive diagnosis of atrial septal defect was made by phonocardiography. Four cases with and four cases without atrial septal defect were classified as having questionable phonocardiographic signs of atrial septal defect. Echocardiographic distinction between those with atrial septal defect and those without atrial septal defect was correct in all cases; quantitative measurement of left-to-right shunt, however, was unsatisfactory. Combined normal findings by x-ray film and echocardiography appeared adequate in all cases for the exclusion of atrial septal defect (six patients). When the six patients who were correctly identified for surgery from the radiological findings are included, there was a total of 12 patients out of 23 (52%:95% confidence limits 31 to 73%) who were evaluated definitively by the non-invasive tests.

Mitral valve replacement in infective endocarditis as prophylaxis against embolism. Identification of patients at risk by 2-dimensional echocardiography.

A 36-yr-old woman and a 46-yr-old man had infective endocarditis of the mitral valve. Examination by 2-dimensional dynamic echocardiography demonstrated large mobile vegetations in both patients, and the display pointed to an ominous risk of embolism. Heart surgery with valve replacement was performed, the main indication being prophylaxis against embolism; the operative findings seemed to justify the assumption of imminent risk of embolism. It is suggested that the display of dynamic morphology of valvular vegetations by 2-dimensional echocardiography can be useful in identifying a subset of patients at high risk of embolism during infective endocarditis. However, more experience is needed before definite conclusions can be drawn regarding the role of early operation as prophylaxis against impending embolism.

Echocardiographic findings in ventricular septal rupture and anterior wall aneurysm complicating myocardial infarction.

Echocardiographic findings in a patient with ventricular septal rupture and anterolateral wall aneurysm complicating myocardial infarction are presented. The findings were confirmed by cardiac catheterization and surgery. Using M-mode ultrasonocardiography one was able to demonstrate and localize the aneurysm as well as the ventricular septal defect which presented as an oblique interventricular communication appearing only during systole. Thus echocardiography supplemented the invasive examinations in exactly revealing the site of ventricular septal rupture. Other echocardiographic features of ventricular septal rupture were right ventricular dilatation, pathological septal motion and abnormal tricuspid valve motion as recently reported by other authors.

The diagnostic challenge of left atrial myxoma. Importance of echocardiographic screening.

Left atrial myxomas are extremely difficult to diagnose since their variable manifestations mimic a host of clinical entities more commonly seen, e.g. mitral stenosis, endocarditis, rheumatic fever, cardiomyopathy or mesenchymosis. At the same time, early diagnosis followed by prompt surgical removal are mandatory to prevent mutilating or lethal complications of the tumor. Six cases of left atrial myxoma were diagnosed in our hospital during 2 1/2 years. We present the case histories, diagnostic procedures and surgical findings, consolidating the unique role of echocardiography in detecting left atrial myxomas. We propose the use of echocardiography as a screening examination for atrial myxomas in the following settings: suspected mitral obstructive disease, suspected endocarditis with negative blood cultures, peripheral embolism or thrombosis in young patients, unexplained cardiac failure and mesenchymosis with uncharacteristic presentation.