Effect of positional changes on inferior vena cava size.

AIM: To study the effect of positional change on inferior vena cava (IVC) diameter. The influence of positional change on IVC size is not well studied. Although the American Society of Echocardiography guidelines for chamber quantification recommend imaging the IVC in the left lateral position, many labs routinely image the IVC from the supine position. METHODS AND RESULTS: Forty-three patients (age 39.5 ± 9.4) with normal echocardiographic findings were studied. Subcostal imaging was used to assess the IVC in the supine and left lateral positions. IVC dimensions, hepatic vein (HV) Doppler and tricuspid regurgitation (TR) jet velocity were measured. IVC systolic and diastolic dimensions were larger in the supine compared with the left lateral position (17.2 ± 4.1 vs. 10.9 ± 4.4 mm, P < 0.001; 16.2 ± 4.5 vs. 9.9 ± 4.4 mm, P < 0.001, respectively). Position had no influence on HV systolic and diastolic peak velocity. (35.4 ± 23.7 vs. 31.8 ± 35.0 cm/s, P = 0.461; 24.2 ± 19.5 vs. 25.4 ± 31.9 cm/s, P = 0.775, respectively). CONCLUSIONS: The IVC dimension is larger in the supine position independent of the cardiac cycle. This may be due to increased intra-abdominal pressure and compression of the IVC by the liver in the left lateral position. HV systolic and diastolic peak Doppler velocities were not influenced by position.

Aneurysmal dilatation of the inferior vena cava.

AIM: Inferior vena cava aneurysms (IVCA) are rare, unlike aortic aneurysms. The diagnosis and treatment is challenging. This study defines clinical and echocardiographic findings in a prospective cohort of sixteen patients with fusiform IVCA. METHODS AND RESULTS: All patients referred to the Mayo Clinic between January 2006 and July 2009 for a clinically indicated echocardiogram (36,128 patients) were screened for a dilated IVC. Sixteen cases of fusiform IVCA were identified. Eleven cases (68.8%) were female. Mean age at presentation was 76 years (range 51-89). Eleven (68.8%) had structural heart disease: with right ventricular (RV) dysfunction in 45.5% (n = 5), moderate or greater tricuspid regurgitation (TR) was seen in 36.4% (n = 4) and RV enlargement was seen in 18.2% (n = 2). The most common clinical indication for echocardiography was dyspnea (25%; n = 4) and heart failure (18.8%; n = 3). The mean IVCA diameter was 4.1 cm (range 3.8-5 cm) and the mean length of the aneurysms was 6.2 cm (range 3.5-8.7 cm), with mean right ventricular systolic pressure of 55 mmHg (range 31-105 mmHg). Five (31.3%) had at least a moderate reduction in right ventricular ejection fraction and five (31.3%) had significant TR. Among these five patients with significant TR, severe TR was present in 80%; (n = 4) and moderate to severe TR was present in 20%; (n = 1). CONCLUSIONS: IVC aneurysms are more common in the elderly, and is associated with an increase in right sided heart pressures, significant TR, and RV dysfunction.

Evaluation of left ventricular rotation in obese subjects by velocity vector imaging.

AIMS: Obesity is a well-known risk factor in the development of cardiovascular disease. We hypothesize that early left ventricular (LV) dysfunction secondary to obesity could be signalled by abnormal LV rotation. METHODS AND RESULTS: This prospective study examined 60 subjects divided into two groups: obese group with body mass index (BMI) >or=30 and control group with BMI <25. The peak rotation, twist, and torsion of the left ventricle were studied in obese and control subjects, using velocity vector imaging. Age and gender were comparable between the two groups. Obese subjects had higher BMI, waist circumference, fasting glucose, triglycerides, systolic and diastolic blood pressure, low-density lipoprotein cholesterol, and lower high-density lipoprotein cholesterol (P < 0.05). In obese subjects, LV mass and LV mass index were increased, and the ratio of mitral early and late diastolic filling velocity was decreased (P < 0.05). In obese subjects, the peak twist and torsion of the left ventricle displayed a lower trend, and the peak rotation of the left ventricle apex decreased significantly (3.81 +/- 2.09 degrees vs. 5.77 +/- 3.27 degrees , P < 0.001). CONCLUSION: Obesity was associated with changes in LV rotation. Velocity vector imaging is a feasible and reproducible echocardiographic technique for the detection of early subclinical LV dysfunction.

Unicuspid aortic valve in children: a systematic review spanning four decades.

BACKGROUND AND AIM OF THE STUDY: To date, the natural history of the unicuspid aortic valve (UAV) has been poorly described in the literature. To study the association between UAV with associated cardiac and extracardiac abnormalities, a systematic review was conducted. METHODS: A computerized search was conducted of the medical literature published between 1st January 1966 and 1st September 2008, using the databases MEDLINE, EMBASE, Web of Science and Cochrane database. RESULTS: Nine articles with 60 pediatric cases (age <15 years) were identified. The mean age at diagnosis was 14 months, the most common presentation of UAV was congestive heart failure due to congenital aortic stenosis, and the most common lesion was isolated aortic stenosis, reported in 19 cases (32%). Associated anomalies included 22 cases (37%) of aortic coarctation, seven (12%) with ventricular septal defect (VSD), three (5%) with patent ductus arteriosus (PDA), and three (5%) with aortic aneurysm. The preoperative diagnosis of UAV was rare, and 33 cases (55%) of pediatric UAV were reported at autopsy or at pathological examination of the surgically excised valves. A total of 26 cases (43%) was treated with either balloon valvoplasty or surgical valvotomy or commissurotomy. CONCLUSION: UAV shares many of the features of bicuspid aortic valve, including valvular dysfunction, aortic dilatation, aortic dissection, and dystrophic calcification. The importance of an early diagnosis of UAV lies in its risk of sudden cardiac death and association with other congenital anomalies, such as PDA, VSD, anomalous coronary arteries, and coarctation of the aorta. Further investigations of UAV are warranted in the pediatric age group with regards to familial incidence, associated aortic histopathological changes, the ideal follow up to monitor complications, and surgical intervention.

Unicuspid aortic valve in adults: a systematic review.

BACKGROUND AND AIM OF THE STUDY: The natural history of the unicuspid aortic valve (UAV) is poorly described in the literature. In order to study the association between UAV with any other cardiac or extra cardiac abnormalities, an evidence-based systematic review was carried out. METHODS: A computerized search was carried out of the medical literature published between 1st January 1966 and 1st September 2008 of the following databases: MEDLINE; EMBASE; Web of Science; and the Cochrane Database. RESULTS: A total of 231 cases of adult UAV was identified in 38 articles. The mean patient age was 42 years, and the most common presenting symptoms reported (in 52 cases) included dyspnea (44%; n=23), angina (21%; n=11), and dizziness or syncope (8%; n=4). The most common lesion in UAV was isolated aortic stenosis (AS) (41%; n=95) and AS with or without aortic regurgitation (28%; n=64). The preoperative diagnosis of UAV is rare, and 139 cases (60%) of UAV were reported at autopsy or by examination of surgically excised valves. Aortic valve replacement was performed in 166 cases (82%). Concomitant aortic surgery was performed in 47 of the UAV cases (23%), either for a dilated or aneurysmal aorta. CONCLUSION: UAV shares many of the features of bicuspid aortic valve, including valvular dysfunction, aortic dilatation, aortic dissection, and dystrophic calcification, although these conditions develop at an earlier age and progress at a faster pace in UAV. Further investigations are warranted regarding the possibility of a familial incidence, associated histopathological changes in the aorta, preoperative diagnostic tools, ideal follow up and surgical intervention.

Critical appraisal on the utility of echocardiography in the management of acute pulmonary embolism.

Echocardiography can be used for rapid and accurate risk stratification of patients with pulmonary embolism to appropriately direct the therapeutic strategies for those at high risk. Echocardiography is an ideal risk stratification tool in this regard because of its easy portability to the emergency room or to the bed side. It can be performed at a relatively low cost and at no risk to the patient. Furthermore, echocardiography allows repetitive noninvasive assessment of the cardiovascular and hemodynamic status of the patient and the response to the therapeutic interventions. Right ventricular hypokinesis, persistent pulmonary hypertension, a patent foramen ovale, and a free floating right heart thrombus are echocardiographic markers that identify patients at a higher risk for morbidity and mortality. Such patients warrant special consideration for thrombolysis or embolectomy.