Biomedical subjects
Publications and source records attributed to Samuel Siu.
Women with some congenital or acquired heart lesions are at increased risk for a number of maternal and neonatal complications during pregnancy. Knowing what constitutes high risk and when to refer to a specialty clinic are key to successfully managing such patients.
BACKGROUND: Previous studies suggested a high incidence of congestive heart failure in patients with single and/or systemic right ventricles. The corresponding risk in an adult population is unknown. METHODS AND RESULTS: A cohort of 188 consecutive adult patients with single or systemic right ventricles was prospectively assessed with gated radionuclide angiography (n=135) or 2D echocardiography (n=188) and followed up clinically. Clinical assessment showed 82.4% of the patients were in New York Heart Association class I or II, 13.3% were in class III, and 4.3% were in class IV. Heart failure occurred in 22.2% of patients with transposition of the great arteries and a Mustard procedure, 32.3% of patients with congenitally corrected transposition of the great arteries, and 40% of Fontan-palliated patients. Symptomatic patients had significantly lower anaerobic thresholds (10.3 +/- 2.8 versus 13.2 +/- 4.8 mL center dot kg(-1) center dot min(-1), P=0.006) and peak (center dot)VO(2) (15.2 +/- 4.8 versus 20.3 +/- 6.8 mL center dot kg(-1) center dot min(-1), P<0.00029). Systemic ventricular ejection fraction in symptomatic versus asymptomatic patients at rest was 34.8 +/- 15.7% versus 46.7 +/- 13.4% (P=0.00001). Mortality was 47.1% among symptomatic patients and 5% among asymptomatic patients at 15.7 years of postoperative follow-up. Seven of 12 patients with potentially correctable surgical lesions died or persisted in heart failure despite surgery. Best predictors for mortality were New York Heart Association class, systemic ejection fraction, and age at operation. CONCLUSIONS: Patients with single or systemic right ventricles have significant risk for heart failure accompanied by high mortality. This study suggests the importance of identifying this group of patients who are at risk for heart failure and considering strategies to preserve ventricular function.
OBJECTIVE: To estimate the impact of contrast stress echocardiography on resource use in the treatment of patients with suspected coronary artery disease (CAD). METHODS: Fifty-nine patients with suspected CAD underwent nuclear perfusion imaging and contrast echocardiography examination. Further treatment was planned after each test and a final treatment was recommended after reviewing the results of both examinations. Medical resources and productivity losses were then collected for a 3-month follow-up period. RESULTS: Diagnosis was possible in 96.6% of patients with nuclear perfusion imaging and 93.2% with contrast echocardiography, resulting in a cost per successful diagnosis of $637 (Can) and $476 (Can), respectively. For the majority of patients (74%), both tests provided the same result, but for 12 patients nuclear imaging suggested abnormal perfusion, whereas contrast echocardiography indicated normal function and for 2 patients it was the opposite situation. Per-patient costs for the total patient population decreased from $316 (Can) after nuclear perfusion imaging to $250 (Can) when results from both tests were known. Three-month follow-up societal costs were $441 (Can) per patient, with hospitalization contributing 58% of this total cost. CONCLUSION: Contrast echocardiography has a similar success rate to nuclear perfusion imaging in diagnosing CAD, but has a 28% lower cost and has the potential of additional cost savings through the elimination of further diagnostic tests.
Primary cardiac tumors are rare, with benign lesions outnumbering malignant ones by a margin of over four to one. Amongst the benign cardiac neoplasms, papillary fibroelastomas are reported second only to myxomas. Papillary fibroelastomas commonly rise from heart valves and their size ranges from a few millimeters to well over 2.0 cm in diameter. While myxomas commonly arise from the interatrial septum, we present the rare example of a large papillary fibroelastoma arising from the left side of the interatrial septum.