Cardiomyopathy: appearances on ECG-gated 64-detector row computed tomography.

Multi-detector row cardiac computed tomography (MDCT) with its high spatial and temporal resolution now has an established clinical role in cardiac imaging. The present review illustrates the MDCT appearances of cardiomyopathy, with reference to the normal myocardium, using multi-planar, near-isotropic imaging, three-dimensional volume rendering, and ECG-gated multi-phasic functional imaging software capabilities of 64-MDCT. MRI and echocardiographic correlations are also provided where appropriate.

Idiopathic dilatation of the pulmonary artery.

Idiopathic dilatation of the pulmonary artery is an uncommon cause of a large main pulmonary artery whose diagnosis is dependent on the exclusion of other causes of central pulmonary artery dilatation. We present four new cases who have been known to have large central pulmonary arteries for many years, and suggest that a long period of observation should be considered to be a further criterion for diagnosis as, in some patients who appear to have this condition, an underlying pathology will become apparent.

Massive pericardial effusion with left-to-right intracardiac shunt.

We describe a 31-year-old man with Down's syndrome who presented with severe chronic hypothyroidism and a massive pericardial effusion. Following partial aspiration of this effusion, he rapidly deteriorated and died. Findings at autopsy revealed him to have an atrioventricular septal defect with shunting at the atrial level. We postulate that, by releasing extrinsic pressure on his right heart by the aspiration, there was sudden shunting of blood from left-to-right, resulting in hypotension, shock, and subsequent death. We highlight the difficulties in management of such a case, and suggest alternative strategies.

Evaluation of an ultrasonically guided venepuncture technique for the placement of permanent pacing electrodes.

We have evaluated a method of puncturing the subclavian vein in its extrathoracic portion using an ultrasound guidance system. Seventy consecutive patients requiring permanent pacemakers were included in the study. The method was successful in 56 (80%) cases (23 dual chamber systems) and unsuitable or unsuccessful in 14 (20%) cases (2 dual chamber systems). The time taken to achieve a successful cannulation of the vein was similar to that taken with conventional subclavian venepuncture (average time taken for each venepuncture was 31 seconds, range 5-130 seconds). There was a significant "learning curve" in that nearly all of the unsuccessful cases were in the first half of the series. There were no major complications. Computerized Tomography (CT) confirms that the point of entry into the subclavian vein using this technique lies outside the thoracic cavity, thereby minimizing the risk of pneumothorax. This approach to the subclavian vein is an easy technique to learn, with few immediate complications and there may be less chance of lead fracture due to subclavian crush in the longer term.

Right hemidiaphragmatic twitching: a complication of bipolar atrial pacing.

A patient with an atrioventricular sequential pacemaker developed rhythmic contractions of the right hemidiaphragm. This was found to be the result of right phrenic nerve stimulation, which was directly related to the wide distance between the poles of an ELA atrial lead when pacing in bipolar mode. Pole separation in current atrial leads is discussed.

Bedside nuclear probe for detection and quantification of left to right intracardiac shunts.

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 flow ratio (QP:QS) was measured by the gamma variate technique. Data were not obtained in four patients because the nuclear probe failed in three patients and one storage disc was corrupted. Data from the gamma camera were lost in another patient. When the size of the shunt measured by the nuclear probe was compared with that measured by the oximetric technique the mean difference (SD of mean difference) was 0.36 (SD 0.78) and when it was compared with the gamma camera it was 0.08 (SD 0.67). Analysis of scatter plots showed that the larger the shunt, the larger the discrepancy. Twenty four of 29 data sets showed complete agreement between the nuclear probe and gamma camera on the size of the shunt. Any differences were small. These data indicate that left to right intracardiac shunts may be measured accurately by a nuclear probe at the bedside in either the coronary care unit or outpatient department.

Radiological and endoscopic diagnosis of infrapapillary carcinoma of the duodenum.

Primary carcinoma of the duodenum is an uncommon cause of epigastric pain, weight loss, and vomiting. The diagnosis is frequently made at a late stage and the prognosis is poor. These tumours may easily be overlooked if the whole of the duodenum is not examined at barium meal or endoscopy. The clinical, radiological and endoscopic findings in three cases are described and the differential diagnosis is discussed. The possibility of an infrapapillary carcinoma of the duodenum should be considered in all patients with unexplained upper gastrointestinal symptoms or blood loss.

Metoclopramide in double contrast barium meals.

A prospective controlled trial was carried out to evaluate the usefulness of the administration of Metoclopramide (Primperan) prior to double contrast barium meal examinations. The results indicated that this did not significantly alter the quality of the examination.