To the Editor: I read with great interest the article entitled “Diagnosis of right-to-left shunt with transcranial Doppler and vertebrobasilar recording,”1 which appeared in Stroke. The authors studied use of vertebrobasilar circulation (VBC) monitoring for detection of right-to-left shunts (RLS) by contrast transcranial Doppler, so-called as “the bubble test.” In comparison with right middle c...

A cadmium telluride nuclear probe with an Elscint gamma camera was used to detect and measure left to right intracardiac shunts at the bedside in 34 patients. Fifteen also had right heart catheterisation and oximetric measurement of the shunt. For the nuclear technique 740 MBq (20 mCi) of technetium-99m pertechnetate was injected into the right antecubital vein and the pulmonary to systemic flo...

We have investigated a technique for quantifying QP/QS in left-to-right cardiac shunts. In this method, the gamma variate, which is fitted to the first-pass portion of the lung curve, is used to generate a curve, which simulates the response of a normal lung curve with systemic recirculation. The difference between this curve and the observed lung curve is then used to calculate QP/QS. This met...

A poor bolus injection results in an unsatisfactory quantitative radionuclide angiocardiogram in as many as 20% of children with possible, left-to-right (L-R) cardiac shunts. Deconvolution analysis was applied to similar studies in experimental animals to determine whether dependence on the input bolus could be minimized. Repeated good-bolus, prolonged (greater than 2.5 sec), or multiple-peak i...

Cross-sectional echocardiographic visualization of the interatrial septum in both normal persons and patients with atrial septal defects has been reported. Although septal defects can generally be visualized, false positives are frequently encountered. This study evaluated whether visualizing the patterns of contrast flow in the region of an apparent atrial septal defect by cross-sectional echo...

septum length, and rims and thickness with electronic caliper edgeto-edge (4). Four main features were used to analyze patients: 1) diameter of the fossa ovalis (FO); 2) presence and length of the channel; 3) presence and degree of atrial septal aneurysm (ASA), following the classification of Olivares et al. (5); and 4) rim thickness. We also analyzed the presence of Eustachian valve and Chiari...

BACKGROUND AND PURPOSE Contrast transthoracic echocardiography (TTCE) is used to screen hereditary hemorrhagic telangiectasia (HHT) patients for right-to-left shunts (RLS) associated with increased stroke risk. We hypothesized that contrast transcranial Doppler (TCDc), shown to be highly sensitive for detecting RLS in patent foramen ovale, will be as comparable to TTCE for screening HHT patient...

We have studied arterial oxygen saturation (SaO2), breathing patterns, and electroencephalographic (EEG) sleep stage during nocturnal sleep in six patients with right-to-left cardiac or intrapulmonary shunts and six patients with chronic bronchitis and emphysema, chosen because they were equally hypoxaemic when awake (SaO2 during wakefulness: bronchitis 74-90%, mean 83%; shunt 77-89%, mean 83%)...