Mechanisms underlying aortic dilatation in congenital aortic valve malformation.
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BACKGROUND: The high incidence of aortic disease in subjects with congenital aortic valve malformations suggests a causative relationship between these 2 conditions. The histological observation in aortic dilatation/aneurysm/dissection is Erdheim cystic medial necrosis (CMN), a noninflammatory loss of smooth muscle cells (SMCs), fragmentation of elastic fibers, and mucoid degeneration. METHODS AND RESULTS: To examine whether apoptosis is 1 of the mechanisms underlying CMN and aortic medial layer SMC loss, ascending aortic wall specimens from 32 patients were collected at cardiothoracic surgery and examined by histochemical staining and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling. From echocardiography results, 4 groups of patients were identified: bicuspid valve carriers with (bi/dil) or without (bi/0) aortic dilatation and tricuspid valve carriers with (tri/dil) or without (tri/0) aortic dilatation. Massive focal apoptosis was observed in the medial layers of bi/dil (mean apoptotic index [mAI], 8.1+/-6.0) and tri/dil (mAI, 8.1+/-8.3) compared with tri/0 (mAI, 0.9+/-1.2; P=0.0079 and P=0.037). In bi/0 (mAI, 9.1+/-5.7) compared with tri/0 (mAI, 0.9+/-1.2), rates of medial SMC apoptosis were increased (P=0.0025). Bi/dil (mean age, 40. 6+/-15.7 years) were significantly younger than tri/dil (mean age, 56.4+/-12.8 years) undergoing the same operation (P=0.0123). CONCLUSIONS: Premature medial layer SMC apoptosis could be part of a genetic program underlying aortic disease in patients with aortic valve malformations. (+info)
Acute assessment of microvascular perfusion patterns by myocardial contrast echocardiography during myocardial infarction: relation to timing and extent of functional recovery.
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OBJECTIVE: To examine the relation between the initial microvascular perfusion pattern, as assessed by intracoronary myocardial contrast echocardiography (MCE), immediately after restoration of TIMI (thrombolysis in myocardial infarction) (TIMI) grade 3 flow during acute myocardial infarction, and the extent and timing of functional recovery in the area at risk. SETTING: Referral centre for interventional cardiology. METHODS: Intracoronary MCE was performed 15 minutes after TIMI grade 3 recanalisation of the infarct artery in 25 patients. Segmental myocardial contrast patterns were graded semiquantitatively (0, none; 0.5, heterogeneous; 1, homogeneous). Functional recovery was assessed by echocardiography on days 9 and 42. RESULTS: Among 174 myocardial segments in the area at risk, wall motion recovery on day 9 was observed in 40% of MCE grade 1 segments but there was no significant recovery in grade 0 or 0.5 segments. On day 42, recovery had occurred in 56% of MCE grade 1 segments (p < 0. 0001 v MCE grade 0 and 0.5; p = 0.0001 v MCE grade 1 on day 9), and 22% of MCE grade 0.5 segments (p = 0.02 v MCE grade 0; p = 0.0005 v MCE grade 0.5 on day 9); MCE grade 0 segments did not recover. Negative predictive value in predicting recovery by contrast enhancement was 95% and 89% by days 9 and 42, respectively. CONCLUSIONS: Contractile recovery occurs earliest in well reperfused segments. Up to one quarter of segments with heterogeneous contrast enhancement show wall motion recovery within the first six weeks. Myocardial perfusion after recanalisation in acute myocardial infarction, even if heterogeneous, is a prerequisite for postischaemic functional recovery. Thus preservation of acute myocardial perfusion is associated with more complete and early functional recovery. (+info)
Urgent homograft aortic root replacement for aortic root abscess in infants and children.
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OBJECTIVE: To assess the results of early homograft aortic root replacement in infants and children with an aortic root abscess. DESIGN: Descriptive study of all patients with an aortic root abscess during 1987-97, identified by retrospective review of the echocardiographic and surgical registries. SETTING: A tertiary referral centre. PATIENTS: Five patients (age 0.6 to 13 years; two female) were identified with an aortic root abscess. Four had no known pre-existing congenital heart abnormality. Three had a misleading presentation and were referred to our hospital with non-cardiac diagnoses (fulminant hepatic failure; adult respiratory distress syndrome; cerebrovascular accident). The other two presented with septicaemia and a murmur, respectively. Blood cultures identified Staphylococcus aureus (n = 3) and Streptococcus pneumoniae (n = 2). Aortic root abscess was diagnosed by transthoracic echocardiography. INTERVENTIONS: Homograft aortic root replacement with coronary reimplantation was performed urgently (median one day after diagnosis). RESULTS: Four patients survived. The youngest died following multiorgan failure, multiple aortic fistulae, three valve involvement, and extensive tissue destruction preventing mitral valve replacement (S pneumoniae). Two of the four survivors have required further surgery: mitral valve replacement (0.3 years later), and pulmonary autograft replacement of the homograft (8.3 years later). All survivors remain in sinus rhythm and New York Heart Association functional class I. CONCLUSIONS: Infective endocarditis should be considered in any child with severe septicaemia or embolic phenomena. Echocardiographic diagnosis of an aortic root abscess indicates uncontrolled infection and impending haemodynamic collapse. Homograft aortic root replacement can be performed successfully in critically ill children with active infection. (+info)
Pacemaker lead infection: echocardiographic features, management, and outcome.
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OBJECTIVE: To compare transthoracic and transoesophageal echocardiography (TTE, TOE) in patients with permanent pacemaker lead infection and to evaluate the safety of medical extraction in cases of large vegetations. METHODS: TTE and TOE were performed in 23 patients with definite pacemaker lead infection. Seventeen patients without previous infection served as a TOE reference for non-infected leads. RESULTS: TTE was positive in seven cases (30%) whereas with TOE three different types of vegetations attached to the leads were visualised in 21 of the 23 cases (91%). Of the 20 patients with vegetations and lead culture, 17 (85%) had bacteriologically active infection. Left sided valvar endocarditis was diagnosed in two patients. In the control group, strands were visualised by TOE in five patients, and vegetations in none. Medical extraction of vegetations >/= 10 mm was performed in 12 patients and was successful in nine (75%) without clinical pulmonary embolism. After 31.2 (19.1) months of follow up (mean (SD)), all patients except one were cured of infection; three died from other causes. CONCLUSIONS: Combined with bacteriological data, vegetations seen on TOE strongly suggest pacemaker lead infection. Normal TTE examinations do not exclude this diagnosis because of its poor sensitivity. Medical extraction of even large vegetations appeared to be safe. (+info)
Dystrophic calcification of the fetal myocardium.
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Intramural cardiac masses were detected antenatally in three fetuses by echocardiography. The masses were initially thought to be rhabdomyomas. All three pregnancies were terminated and histology showed dystrophic calcification in all, with no evidence of tumour. Therefore, dystrophic calcification of the fetal myocardium may have a similar appearance to single or multiple rhabdomyomas. This should be considered when counselling parents after detection of masses in the fetal heart, particularly when considering the risk of associated tuberous sclerosis. (+info)
Combined aortic and mitral stenosis in mucopolysaccharidosis type I-S (Ullrich-Scheie syndrome).
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The genetic mucopolysaccharidosis syndromes (MPS) are autosomal recessive inborn errors of metabolism. Heart valve involvement in MPS is not uncommon but only a few case reports of successful cardiac surgery are available. In particular, reports of combined aortic and mitral stenosis associated with MPS type I-S are very rare. Both type I and type VI MPS are associated with significant left sided valvar heart disease that requires surgical valve replacement because of irregular valve thickening, fibrosis, and calcification. A 35 year old man had severe mitral valve stenosis after successful surgical replacement of a stenotic aortic valve. Valvar heart disease was investigated by cardiac ultrasound and left heart catheterisation. Histomorphological characterisation of the affected mitral valve was performed. The case illustrates typically associated clinical features of cardiac and extracardiac abnormalities found in MPS type I-S. (+info)
Left ventricular hypertrophy in hypertension: stimuli, patterns, and consequences.
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Left ventricular (LV) size in childhood closely parallels body size, whereas in adulthood LV mass is increasingly affected by effects of obesity, hypertension, the level of cardiac volume load, and the level of LV myocardial contractility. Recently, additional independent associations of diabetes, arterial structure and function and as yet unknown genes with higher LV mass have been defined; angiotensin II and insulin have also been suggested to be additive stimuli to LV hypertrophy. Consideration of the level of LV mass and of the LV wall thickness/chamber radius ratio (relative wall thickness) has identified four different geometric patterns of LV adaptation to hypertension, including concentric LV hypertrophy (increased mass and wall thickness), eccentric hypertrophy (increased mass, normal relative wall thickness), concentric remodeling (increased relative wall thickness with normal mass) and normal LV geometry. Concentric hypertrophy is associated with especially high arterial pressure while eccentric hypertrophy is associated with obesity and elevated volume load. Numerous studies show that increased LV mass predicts cardiovascular events and death independently of all conventional risk factors; initial studies have also identified adverse implications of low LV midwall function and high relative wall thickness. Pioneer studies strongly suggest that reversal of LV hypertrophy is associated with an improved prognosis. (+info)
Effects of spironolactone and angiotensin-converting enzyme inhibitor on left ventricular hypertrophy in patients with essential hypertension.
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There is increasing evidence for important cardiovascular effects of aldosterone via classical mineralocorticoid receptors in the heart. Administration of aldosterone with excess salt produces both cardiac hypertrophy and interstitial cardiac fibrosis in rats, and concomitant administration of potassium canrenoate at a dose that only modestly lowers blood pressure completely blocks the cardiac effects of aldosterone. In the present study, we examined the effect on left ventricular hypertrophy of adding a low dose of the mineralocorticoid receptor antagonist spironolactone (25 mg/d) to an angiotensin-converting enzyme inhibitor (enalapril maleate) in patients with essential hypertension. Eighteen untreated patients with moderate to severe essential hypertension based on the WHO/ISH guidelines participated in this study. Subjects were treated with either an angiotensin-converting enzyme inhibitor alone (group I: 10 patients, 4 men and 6 women, mean age 56 +/- 18 yr) or an angiotensin-converting enzyme inhibitor plus spironolactone (group II: 8 patients, 3 men and 5 women, mean age 59 +/- 14 yr) for 9 mo. Left ventricular mass index, various echocardiographic variables, mean blood pressure, plasma renin activity, and plasma aldosterone concentration before treatment were similar in the two groups. Blood pressure of both groups decreased significantly and similarly after antihypertensive treatment (group I, 136 +/- 9/82 +/- 9 mmHg; group II, 133 +/- 9/85 +/- 10 mmHg). Left ventricular mass index also decreased significantly in both groups (group I, -10.2 +/- 7.1%; group II, -18.1 +/- 6.9%). The extent of reduction was significantly greater in the spironolactone group (group II) (p < 0.05 vs. group I). In group II patients, spironolactone did not cause any side effects during the observation period. We conclude that spironolactone may have beneficial effects on left ventricular hypertrophy in patients with essential hypertension who are receiving an angiotensin-converting enzyme inhibitor. (+info)