Kimberly A. Krabill

Echocardiographic versus cardiac catheterization diagnosis of infants with congenital heart disease requiring cardiac surgery

The success of noninvasive preoperative evaluation of infants with congenital heart disease using cardiac ultrasound depends not only on diagnostic accuracy, but also on risk of morbidity and mortality as compared with infants who undergo cardiac catheterization. Fifty-six infants (age 10 weeks or younger) with coarctation of the aorta (n = 16), coarctation with ventricular septal defect (n = 12), valvar aortic stenosis (n = 10) or total anomalous pulmonary venous connection (n = 18) were examined. Thirty-one underwent noninvasive preoperative assessment and 25 underwent evaluation including cardiac catheterization. Age, level and duration of support, pH, renal function, mortality, complications of cardiac catheterization and errors of diagnosis were compared. Significant differences between the 2 groups were more frequent preoperative use of prostaglandin E1 and shorter hospital stay in the noninvasively evaluated coarctation group. Of the infants with coarctation and ventricular septal defect, 1 who had cardiac catheterization required renal transplantation and 1 evaluated noninvasively required surgery at age 3 months for mitral stenosis not discovered on preoperative evaluation. One noninvasively evaluated infant with total anomalous pulmonary venous connection had a stenotic communication between the pulmonary venous confluence and the left atrium not detected by ultrasound. Surgery was successful in the latter 2 infants. Noninvasive preoperative diagnosis of some infants with congenital heart disease can be performed without increasing the risk of operative morbidity and mortality. Eliminating cardiac catheterization reduces hospital costs, decreases total numbers of catheterizations performed and influences the structure of training programs.

Factors influencing the structure and shape of stenotic and regurgitant jets an in vitro investigation using doppler color flow mapping and optical flow visualization

To evaluate factors influencing the structure and shape of stenotic and regurgitant jets, Doppler color flow mapping and optical flow visualization studies were performed with use of a syringe model with a constant rate of ejection to simulate jets of valvular regurgitation and a pulsatile flow model of the right heart chambers to simulate jets of mild, moderate and severe valvular pulmonary stenosis. Ink-(0 to 40%) glycerol-water jets (viscosity 1 to 3.5 centiPoise) were produced by injecting the fluid at a constant rate into a 10 gallon rectangular reservoir of the same still fluid through 1.4 and 3.4 mm needles. The Doppler color flow scanners imaged the laminar jet length within 3 mm of actual jet length (2 to 6 cm) and the jet width within 2 to 3 mm of the actual jet width. Jet flows with Reynolds numbers ranging from 230 to 1,200 injected into still fluid yielded jet length/width ratios that decreased with increasing Reynolds numbers and leveled off to a length/width ratio of 5-6:1 at a Reynolds number near 600. When the fluid reservoir was swirled to better mimic the effect of flow entering the same cardiac chamber from a second source, the jets showed diminution of the jet length/width ratio and a clearly defined zone of turbulence. Studies of the pulsatile flow model were performed at cardiac outputs of 1 to 6 liters/min for the normal and each stenotic valve. Mild stenosis had an orifice area of 2.8 cm2, moderate stenosis an area of 1.0 cm2 and severe stenosis an area of 0.5 cm2. Laminar jet length represented the length of the total jet, which had a symmetric width and was measured from the valve opening to a region where the jet exhibited a spray effect. Laminar jet lengths (0.2 to 1.1 cm) were imaged by Doppler color flow mapping and optical visualization only in the moderate and severely stenotic valves and only at flows less than or equal to 3 liters/min (mean Reynolds numbers less than or equal to 3,470). Beyond this flow rate the jets exhibited a spray effect. Laminar jet length/width ratio approached unity with an increased amount of valvular stenosis and higher flow volumes (cardiac output). Proximal aliasing was present in each valve studied. the length of aliasing (0 to 3.2 cm) proximal to the valve was longer with increased flow rates and increased amounts of stenosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Evaluation of coronary artery anatomy in patients with tetralogy of Fallot by two-dimensional echocardiography.

A major coronary artery crossing the right ventricular outflow tract in patients with tetralogy of Fallot interferes with a transannular patch, and preoperative detection of this artery is important. We evaluated the ability of two-dimensional echocardiography to define noninvasively the coronary artery anatomy in 37 consecutive patients (age range, 1 day to 18 years; mean age, 40.9 months). The origin and distribution of the right anterior descending and circumflex coronary arteries, as well as any anteriorly coursing vessel, were examined from parasternal views. Complete studies were obtained in 29 (78%) of the 37 patients. Coronary artery anatomy was determined to be normal by echocardiography in 20 (69%) of the 29 patients. An anterior vessel across the right ventricular outflow tract was detected in the remaining nine patients. Six patients had an anterior descending artery from the left main coronary artery (paired anterior descending arteries in three patients, a right anterior descending artery from the left main coronary artery in two patients, and a right coronary-to-pulmonary artery fistula in one patient). Three patients had no anterior descending artery from the left main coronary artery (anterior descending artery from the right main coronary artery in two patients, and anterior descending and circumflex arteries from the right main coronary artery in one patient). Angiography, surgery, or autopsy confirmed the diagnoses in all but the final patient in whom the anterior descending artery arose from the right main coronary artery as observed at surgery, but the circumflex artery was not seen. Accurate evaluation of coronary artery anatomy is possible by echocardiography in the majority of patients with tetralogy of Fallot. Noninvasive identification of a major coronary artery coursing anteriorly can influence the timing of cardiac catheterization and surgery and the need for angiography.

Migraineurs with patent foramen ovale have larger right-to-left shunt despite similar atrial septal characteristics.

The objective of the study was to assess differences in proportion of large right-to-left shunt (RLS) and atrial septal characteristics between migraineurs and non-migraineurs referred for transcatheter closure of patent foramen ovale (PF0). This retrospective study took place in a large metropolitan medical centre. The patients were migraineurs with aura (n=52), migraineurs without aura (n=19) and non-migraineurs (n=149). RLS was evaluated before closure using bilateral power m-mode transcranial Doppler at rest and after calibrated, sustained Valsalva manoeuvre, and graded with a validated 0–5 scale. Intracardiac echocardiography was used to assess atrial septal characteristics. Migraineurs had a higher proportion of large RLS (Grade IV or V) than nonmigraineurs at rest and after calibrated Valsalva (rest, p=0.04; Valsalva, p=0.01). Atrial septal characteristics were similar between groups. Migraine is associated with larger RLS at rest and strain; however migraine status does not predict PFO characteristics.

Frequency of Migraine Headache Relief Following Patent Foramen Ovale "Closure" Despite Residual Right-to-Left Shunt

Retrospective studies have shown improvement in migraines after patent foramen ovale (PFO) closure. To date, no study has evaluated whether the completeness of closure affects headache status; therefore, the objective of this study was to evaluate the impact of residual right-to-left shunt (RLS) on migraine symptoms after transcatheter PFO closure in migraineurs with and without aura. This was a small-series, single-center, retrospective analysis of late follow-up data on 77 patients with presumed paradoxical embolism and migraine who underwent PFO closure for secondary stroke prevention. Power M-mode transcranial Doppler was used to assess RLS at baseline and 6 and 12 months after closure. A standardized migraine questionnaire was administered at baseline and 6, 12, and 24 months after closure. Fifty-five (71%) patients had migraine with aura. Final closure and migraine status were available for 67 patients; 23 (34%) had incomplete PFO closure, defined as 30 embolic tracks detected at final power M-mode transcranial Doppler examination (median 366 days, 95% confidence interval 332 to 474). Migraine relief (> or = 50% reduction in frequency) was independent of closure status (77% complete closure vs 83% incomplete closure, p = 0.76) at late follow-up (540 days, 95% confidence interval 537 to 711). Migraineurs with aura were 4.5 times more likely to experience migraine relief than migraineurs without aura. In conclusion, migraine relief may occur despite residual RLS after transcatheter PFO closure, which may suggest a reduction in RLS burden below a neuronal threshold that triggers migraine; however, this warrants further investigation. Migraine with aura may be an independent predictor of relief after PFO closure.

Cardiovascular function in children following bone marrow transplant: a cross-sectional study

Sixty-three patients who had undergone a BMT at age ⩽18 years were evaluated cross-sectionally to determine cardiac function as well as the long-term prevalence, types, severity, and risk factors of cardiac abnormalities. Patients were ⩾1 year post-BMT and were evaluated by history, resting ECG, echocardiography (ECHO), exercise treadmill test, chest X-ray, pulmonary function tests and review of past cardiac studies. Patients were assigned a New York Heart Association (NYHA) class based on an activity and cardiac symptoms questionnaire. Pretransplant preparative regimens included high-dose cyclophosphamide (CY) and total body/lymphoid irradiation (n = 38), CY in combination with other chemotherapy (n = 22), and other drug combinations (n = 3). Forty patients (63.5%) had received prior anthracyclines (median 307 mg/m2). Patients’ ages ranged from 1.9 to 32 years (median 10.9 years) with median follow-up of 3.3 years (range 1–16.3 years). Twenty-six patients (41.3%) had a cardiac abnormality detected at follow-up. In 21 patients the abnormal finding had not been present at the pre-BMT evaluation. Ten patients (16.4%) had resting ECG abnormalities. Left ventricular ejection fraction (LVEF) by ECHO was mildly decreased to 50–54% in three patients and markedly decreased to 40% in one patient. Only one patient (1.7%) developed a mildly abnormal shortening fraction of 27%. All patients with ECHO abnormalities were asymptomatic. Twenty-three of 31 patients ⩾9 years of age (74%) who underwent a treadmill exercise test had a borderline or abnormal response to exercise. There was no correlation between demographic factors, previous therapy, preparative regimen or length of follow-up with the post-BMT ECG, ECHO and treadmill abnormalities. Overall, eight patients (12.7%) were symptomatic and NYHA class II or III, and all had abnormal exercise tests. The presence of symptoms and NYHA class were predictors for oxygen consumption during exercise (P = 0.03 and 0.02, respectively) and tended to predict overall treadmill results also. Late cardiac abnormalities do occur following BMT in childhood and thus, there is a clear need for continued, serial long-term cardiac evaluation in transplant survivors. Evaluations should include exercise stress testing to detect inadequate cardiac output as well as oxygen consumption during exercise.

Rest and exercise hemodynamics in pulmonary stenosis: comparison of children and adults

To better understand the hemodynamics of pulmonary stenosis (PS), 24 adults and 53 children with similar degrees of PS who had undergone cardiac catheterization at rest and during supine exercise were retrospectively studied. Three groups were defined. Group I consisted of 9 adults and 18 children with a pulmonary valve area of less than 0.5 cm2/m2; group II, 6 adults and 25 children with a pulmonary valve area of 0.5 to 1.0 cm2/m2; and group III, 9 adults and 10 children with pulmonary valve area of more than 1.0 cm2/m2. The mean ages of the adults were 29, 26 and 22 years for groups I, II, and III, respectively. The mean ages of the children were 11, 10 and 9 years for groups I, II and III, respectively. The pertinent data collected from catheterization included oxygen consumption, cardiac rate and index, arterial venous oxygen difference, stroke index, right ventricular (RV) systolic pressure and RV end-diastolic pressure. Adults and children in groups II and III had an appropriate response to exercise. Group I children responded abnormally by increasing their RV end-diastolic pressure and decreasing their stroke index. In group I adults both of these variables increased. Group I adults exhibited a significantly lower cardiac index at rest and exercise secondary to a significantly lower absolute cardiac rate. Long-standing severe PS results in hemodynamic compromise. Hence, early relief of PS is recommended.

Diagnosis of Secondary Source of Right-to-Left Shunt With Balloon Occlusion of Patent Foramen Ovale and Power M-Mode Transcranial Doppler

OBJECTIVES We sought to assess the prevalence of secondary right-to-left circulatory shunt (RLS) in patients undergoing transcatheter closure of patent foramen ovale (PFO) as detected by power M-mode transcranial Doppler (TCD) and intracardiac echocardiography. BACKGROUND Prevalence of residual RLS in late follow-up after PFO closure may be as high as 34%. Other cardiac and noncardiac sources of RLS may coexist and obscure PFO closure evaluation. METHODS Eighty-eight patients who underwent transcatheter PFO closure to prevent recurrent paradoxical cerebral embolism between June 2005 and December 2006 were evaluated for a secondary source of RLS. Before device deployment, a sizing balloon was inflated in the PFO tunnel and agitated saline contrast was injected into the inferior vena cava. Clinically significant secondary RLS was defined as >10 embolic tracks on TCD at rest or immediately after calibrated (40 mm Hg), sustained (10 s) respiratory strain, with corresponding negative color-flow Doppler. Late residual RLS was evaluated in all patients with TCD and transthoracic echocardiography (mean: 192 days; 95% confidence interval [CI]: 161 to 223 days). RESULTS The sample (n = 84) was 59% female, age 49 +/- 14 years. Seventeen patients (20%; 95% CI: 11.7 to 28.8) had secondary RLS during balloon occlusion. At late follow-up (n = 66), 13 of 14 (93%) patients with secondary RLS and 23 of 52 (44%) patients without secondary RLS had residual RLS (p = 0.002). CONCLUSIONS This is the first report to systematically assess the prevalence of secondary RLS in patients undergoing PFO closure. Residual RLS detected by TCD may be due to secondary RLS, which may have implications for clinical outcomes.

Dissecting transverse aortic arch aneurysm after percutaneous transluminal balloon dilation angioplasty of an aortic coarctation

SummaryPercutaneous transluminal balloon dilation angioplasty of an aortic coarctation was done in a one-day-old boy. The infant died 10 h later during aortic valvotomy. A dissecting aneurysm of the aortic arch was present at autopsy.

Transcatheter closure of congenital coronary arterial fistula with a detachable balloon.

SummaryCoronary arterial fistulae are rare congenital cardiac defects that typically are treated by surgery. A case of transcatheter closure of a left anterior descending coronary artery to right ventricular fistula with a detachable balloon is described in a 16-month-old child. The fistula was easily occluded without complication. Follow-up 1.5 years later revealed normal ventricular function and no recurrence of the fistula. Detachable balloon occlusion of coronary arterial fistula is feasible in patients as young as 4 months.