Doppler-echocardiographic assessment of pulmonary regurgitation in adults with repaired tetralogy of Fallot: comparison with cardiovascular magnetic resonance imaging

Aims

The purpose of this study was to compare the noninvasive assessment of severity of pulmonary regurgitation with Doppler echocardiography versus cardiovascular magnetic resonance imaging (CMR) in adult patients with repaired tetralogy of Fallot (rTOF).

Methods

We studied 52 (22 females) consecutive patients (aged 32 ± 2 years, 23 ± 5 years after rTOF) using Doppler echocardiography and compared these findings with CMR. From the continuous-wave Doppler trace, the duration of pulmonary regurgitation and of total diastole was measured and the ratio between the 2 was defined as pulmonary regurgitation index (PRi). Pulmonary regurgitant fraction (PRF) was assessed with flow phase velocity mapping with CMR.

Results

Patients were divided into 2 groups according to the median value (24.5%) of PRF measured by CMR: Group I (26 patients) with PRF ≤24.5% and Group II with PRF >24.5%. There was no difference between patients' age, sex, or age at repair between the 2 groups. More patients from Group II had a right ventricular outflow or transannular patch repair compared to Group I (12/26 [46%] vs 6/26 [23%], P < .01). Mean pulmonary regurgitation time was shorter (340 ± 60 vs 440 ± 135 ms, P = .001) and PRi was lower (0.61 ± 0.11 vs 0.91 ± 0.11, P < .001) in Group II compared to Group I. Color Doppler regurgitant jet was also broader in Group II (1.4 ± 0.4 vs 0.7 ± 0.5 cm, P < .001), signifying more severe pulmonary regurgitation. Doppler-measured PRi correlated closely with CMR regurgitant fraction (r = −0.82, P < .001) and with color Doppler pulmonary regurgitant jet width (r = −0.66, P < .001); the latter correlated with PRF assessed with CMR (r = 0.72, P < .001). A PRi <0.77 had 100% sensitivity and 84.6% specificity for identifying patients with pulmonary regurgitant fraction >24.5%, with a predictive accuracy of 95%. Furthermore, echocardiographically-assessed right ventricular end-diastolic dimensions correlated with CMR end-diastolic volume index (r = 0.49, P < .001 ).

Conclusions

Pulmonary regurgitation is common in asymptomatic adults with rTOF. Severity of pulmonary regurgitation and its effects on right ventricular dimensions in these patients can be assessed noninvasively by Doppler echocardiography and CMR, with reasonable agreement between the 2 techniques.     

Computed tomographic angiography in tetralogy of Fallot

Echocardiography is often inadequate for imaging tetralogy of Fallot, prompting cineangiography. This study prospectively evaluated multidetector computed tomographic angiography for preoperative evaluation of tetralogy of Fallot in 112 consecutive patients. Forty-eight had nonconfluent or hypoplastic pulmonary arteries (mean z-score, -2; range, -11.1-0.13) permitting only palliative or no surgery; 64 had adequate pulmonary artery anatomy (mean z-score, 0.59; range, -2.53-3.4) allowing total repair. The surgical data of 50 patients who underwent total correction were compared with transthoracic echocardiography and multidetector computed tomographic angiography findings. Multidetector computed tomographic angiography tended to reveal unsuspected collaterals and coronary abnormalities besides outlining the right ventricular outflow tract and pulmonary artery branches. The branch pulmonary artery diameter z-score was the most important determinant of surgical strategy, with the worst figures being associated with no surgical options or palliative surgery, and the best figures leading to corrective surgery. The mean radiation dose was 3.45 mSv. Multidetector computed tomographic angiography is a powerful supplement to echocardiography in the preoperative evaluation of tetralogy of Fallot.     

Cardiovascular magnetic resonance in the follow-up of patients with corrected tetralogy of Fallot: a review

Cardiovascular magnetic resonance (CMR) is becoming an important tool in the clinical management of patients with congenital heart disease. Because of the diverse problems patients may face after initial correction for tetralogy of Fallot and the large amount of CMR techniques that can be applied, creating a patient-orientated imaging protocol is a difficult issue. Although it is still not certain what the impact of some parameters, provided by CMR, should be on clinical decision making, new techniques are being developed and applied. In this report, we review the current clinical issues in patients with tetralogy of Fallot and review the current implication and limitations of CMR in this patient category.     

Transvenous approach to coronary angiography in infants with tetralogy of Fallot

A new technique is offered for selective imaging of the coronary arterial system from a transvenous approach in patients with tetralogy of Fallot as an alternative to other traditional approaches. This technique should identify important coronary anomalies while avoiding femoral arterial cannulation and compromise.     

Cardiac magnetic resonance imaging correlates of exercise capacity in patients with surgically repaired tetralogy of Fallot

Objective exercise testing in patients with repaired tetralogy of Fallot frequently identifies gross deficiencies in exercise capacity. These findings are typically attributed to right ventricular dysfunction, pulmonary valve regurgitation, and pulmonary artery stenosis and are used to justify referrals for surgical or transcatheter interventions. However, the relation between right-sided cardiac abnormalities and exercise capacity in this patient group is poorly understood. Cardiac magnetic resonance imaging correlates of exercise capacity in 37 patients with repaired TOF were retrospectively examined. In conclusion, on multivariate analysis, right ventricular ejection fraction was the only cardiac magnetic resonance imaging predictor of percentage of predicted peak oxygen consumption, oxygen consumption at ventilatory anaerobic threshold, and oxygen pulse.     

Echocardiographic diagnosis of tetralogy of Fallot

The echocardiographic features of tetralogy of Fallot were defined in 25 patients with this malformation proved by cardiac catheterization. The echocardiographic characteristic that was present in all patients and that was most sensitive was the abrupt ending of the interventricular septal echoes with the aorta overriding the ventricular septal defect. The following additional echocardiographic features were frequently demonstrated in these 25 patients: right ventricular enlargement (20 patients), hypertrophy of the interventricular septum (20 patients), diminution of the right ventricular outflow tract (21 patients) and widening of the aorta (24 patients). The suggestion is made that the most specific echocardiographic pattern of tetralogy of Fallot is the finding of several echocardiographic abnormalities rather than the single feature of aortic overriding. Recognition of the altered anatomic relation coupled with a complete echocardiographic evaluation of all cardiac structures is a reliable means of diagnosing tetralogy of Fallot.     

Pulmonary embolism: comparison of angiography with spiral computed tomography,magnetic resonance angiography,and real-time magnetic resonance imaging

In the last decade, spiral computed tomography (CT) and magnetic resonance (MR) angiography (MRA) have become a viable alternative to conventional angiography in the diagnosis of acute pulmonary embolism. However, patients with dyspnea are often unable to hold their breath for a longer time and thus image degradation is frequently observed. Consequently, an imaging sequence that allows free breathing is desirable. The aim of this animal study was to compare contrast-enhanced spiral CT, MRA and a real-time MR sequence, the latter without breath-hold, with pulmonary angiography as reference gold standard. Nine pigs with artificially induced pulmonary embolism underwent this multimodality comparison. All images were independently evaluated for the presence of pulmonary emboli by two reviewers. Forty-three filling defects were detected by conventional angiography on lobar and segmental levels. Sensitivity of CT images was 72.1 and 69.8% for Readers 1 and 2, respectively, and sensitivity of MRA images was 79.1 and 81.4%. With real-time MR imaging, however, the detection rate was 97.7% for both readers. We conclude that, under experimental conditions, real-time MR imaging without the use of radiation or iodinated contrast material is comparable with angiography in the detection of pulmonary emboli.     

Budd-Chiari syndrome： Diagnosis with three-dimensional contrast-enhanced magnetic resonance angiography

AIM: To evaluate the role of three-dimensional contrast-enhanced magnetic resonance angiography (3D CE MRA) in the diagnosis of Budd-Chiari syndrome (BCS). METHODS: Twenty-three patients with BCS underwent 3D CE MRA examination, in which 13 cases were secondary to either hepatocellular carcinoma (11 cases), right adrenalcarcinoma (1 case) or thrombophlebitis (1 case) and 10 suffered from primary BCS. The patency of the inferior vena cava (IVC), hepatic and portal veins as well as the presence of intra- and extrahepatic collaterals, liver parenchymal abnormalities and porto-systemic varices were evaluated. Inferior vena cavography was performed in 10 cases. The diagnosis of IVC obstruction by 3D CE MRA was compared with that demonstrated by inferior vena cavography.RESULTS: The major features of BCS could be clearly displayed on 3D CE MRA. Positive hepatic venous signs included tumor thrombosis (9 cases), tumor compression (2 cases), nonvisualization (4 cases) and focal stenosis (2 cases). Positive IVC findings were noted as severe stenosis or occlusion (10 cases), tumor invasion (2 cases), thrombosis (3 cases), thrombophlebitis (1 case) and septum formation (3 cases). Intrahepatic collaterals were shown in 9 patients,2 of them with “spider web“ sign. The displayed extrahepatic collaterals included dilated azygos and hemi-azygos veins (13 cases) and left renal-inferior phrenic-pericardiophrenic veins (2 cases). The occlusion of the left intrahepatic portal veins was found in 2 cases. Porto-systemic varices were detected in 10 patients. Liver parenchymal abnormalities displayed by 3D CE MRA were enlargement of the caudate lobe (7 cases), heterogenous enhancement (18 cases) and complicated tumors (13 cases). Compared with the inferior vena cavography performed in 10 cases, the accuracy of 3D CE MRA was 100 % in the diagnosis of IVC obstruction.CONCLUSION: 3D CE MRA can display the major features of BCS and provide an accurate diagnosis.     

Results of routine preoperative coronary angiography in tetralogy of Fallot.

In the surgical repair of tetralogy of Fallot, morvidity and mortality are increased by certain coronary anomalies, in particular, an anterior descending branch originating from the right coronary artery or a single coronary artery in which a large coronary branch runs across the pulmonary outflow tract. In series of 94 patients with tetralogy of Fallot who underwent cardiac catheterization, coronary artery visualization was attempted routinely, most often by flush aortography using a venous catheter. Diagnostic coronary visualization was obtained in 84 patients (89%). In these, the incidence of recognized coronary anomalies was 5%; anterior decending from the right coronary artery in four patients (4%), and singly left coronary in one patient (1%). In 195 autopsied cases of tetralogy, the incidence of coronary anomalies was also 5%. Routine preoperative demonstration of the coronary artery anatomy in tetralogy patients usually can be accomplished satisfactorily and conveniently by transvenous flush aortography.     

Factors associated with impaired clinical status in long-term survivors of tetralogy of Fallot repair evaluated by magnetic resonance imaging

OBJECTIVES: The purpose of this study was to identify independent factors associated with impaired clinical status in late survivors of tetralogy of Fallot (TOF) repair. BACKGROUND: Repair of TOF often results in chronic pulmonary regurgitation (PR) and right ventricular (RV) dilation, which have been linked to late morbidity and mortality. However, determinants of clinical status late after TOF repair have not been fully characterized. METHODS: The clinical and laboratory data of 100 consecutive patients with repaired TOF (median 21 years after repair) who completed a cardiac magnetic resonance imaging protocol were analyzed. Impaired clinical status was defined as New York Heart Association (NYHA) functional class > or =III. RESULTS: Of the patients, 88 were in NYHA functional class I or II and 12 were in NYHA functional class III. The degree of PR and indexed RV end-diastolic volume were not associated with impaired clinical status. By multivariate analysis, a lower left ventricular (LV) ejection fraction (EF) (odds ratio [OR] = 3.88 for 10% decrease, p = 0.002) and older age at TOF repair (OR = 1.70 for 5-year increase, p = 0.013) were the strongest independent factors associated with impaired clinical status. Among RV variables, a lower RV EF was the strongest independent factors associated with poor clinical status (OR = 2.41 for 10% decrease, p = 0.01). The LV EF correlated with RV EF (r = 0.58, p < 0.001). CONCLUSIONS: Moderate or severe LV or RV systolic dysfunction, but not PR fraction or RV diastolic dimensions, is independently associated with impaired clinical status in long-term survivors of TOF repair. The close relationship between LV EF and RV EF suggests unfavorable ventricular-ventricular interaction.     

Likelihood ratios in the diagnosis of renal artery stenosis by magnetic resonance angiography compared with renal angiography

BACKGROUND: Renal angiography (RA) is considered to be the gold standard for the diagnosis of renal artery stenosis (RAS). However, it is invasive and potentially harmful; hence there is a need for an optimal noninvasive test. Magnetic resonance angiography (MRA) is currently accepted as the optimal noninvasive test by many. However, its major drawback is its inability to grade quantitatively the degree of stenosis. In this study, likelihood ratios (LR) were used to compare the diagnostic accuracy of MRA with that of RA. METHODS: To test the hypothesis that semiquantitatively graded MRA would correlate with RA, a retrospective analysis was performed to determine the LR of MRA to diagnose RAS compared with RA. It was believed that LR > or = 10.0 or < or =0.1 might generate conclusive changes from pretest to post-test probabilities. In this study a total of 94 renal arteries from 48 patients were analyzed for RAS by MRA and RA. Stenoses were graded by MRA as mild (<50%), moderate (50% to 75%), or severe (>75%); and by RA as <75% or > or =75% stenosis. RESULTS: The LR was 0.13 (95% CI = 0.09 to 0.19) for mild stenosis, 0.11 (95% CI = 0.08 to 0.15) for moderate stenosis, and 2.2 (95% CI = 1.9 to 3.1) for severe stenosis by MRA. CONCLUSIONS: Nonsevere stenosis can be sufficiently diagnosed by MRA and may not warrant RA. However, it may be insufficiently precise to establish severe RAS based on LR results. Therefore, for severe RAS by MRA, the decision to obtain RA can be made with the help of post-test probability, which is determined using pretest probability and LR.     

Vectorcardiography in the differential diagnosis of tetralogy and trilogy of Fallot

Vectorcardiograms and electrocardiograms were studied in 16 cases of tetralogy of Fallot and in 21 cases of valvular pulmonary stenosis with or without atrial septal defect.

The data suggest that it is possible to recognize the type of right ventricular hypertrophy present in these congenital heart diseases, as well as the manifestation of the electromotive forces of the left ventricle.

Three main conclusions are derived: (1) the electrical tracings, and particularly the vectorcardiograrms, usually show the presence of right ventricular hypertrophy of the regional type in tetralogy of Fallot and of global type in trilogy; (2) in the presence of right bundle branch block of intermediate or advanced degree the electrical behavior is similar in both tetralogy and trilogy; (3) in the two groups studied here, it is possible to recognize the electrical manifestation of the left ventricle, particularly as a function of the area of the R loop in the frontal plane vectorcardiogram.     

The use of intravenous digital subtraction angiography in the evaluation of tetralogy of Fallot

Sixteen patients with tetralogy of Fallot were studied with intravenous digital subtraction angiography (DSA). Of these, 11 were males and five were females, ranging in age from 26 months to 54 years, with a mean age of 22 years at the time of the initial study. Twenty-two DSA studies were performed in the 16 patients, in seven patients preoperatively, in 12 patients postoperatively, and in three patients both pre- and postoperatively. In the seven patients studied preoperatively, all DSA studies were considered technically adequate as corroborative evidence in the diagnosis of tetralogy of Fallot. All associated cardiac abnormalities were adequately demonstrated. The 16 postoperative studies on 12 patients were performed to evaluate the adequacy of the surgery and/or postoperative complications. These studies were judged as technically satisfactory. The authors utilized intravenous DSA in the pre- and postoperative evaluation of 16 patients with tetralogy of Fallot and found that reliable angiographic information was provided and that this technique may serve as a useful adjunct with other noninvasive and invasive tests in the preoperative and postoperative evaluation of these patients.     

First diagnosis of Fallot tetralogy in a 74-year-old man

Zusammenfassung Die Fallotsche Tetralogie gilt im späteren Kindes- und Erwachsenalter als häufigster zyanotischer Herzfehler und tritt bei ca. 0,25 Neugeborenen unter tausend Geburten auf. Wegen der niedrigen Überlebenschance der Patienten ohne frühe chirurgische Korrektur konnten die Spätfolgen dieses Krankheitsbildes nur in wenigen Fällen untersucht werden. Wir berichten über ein komplexes Beispiel einer Fallot-Tetralogie bei einem Erwachsenen, der ohne chirurgische oder medizinische Behandlung überlebte. Seit Kindheit war ein Ventrikelseptumdefekt bekannt. Die Diagnose der Fallotschen Tetralogie wurde im Alter von 74 Jahren gestellt, als der Patient zur invasiven Diagnostik und ICD-Implantation wegen einer dokumentierten ventrikulären Tachykardie mit nachfolgender Synkope in unsere Einrichtung aufgenommen wurde.