High resolution computed tomographic assessment of airway wall thickness in chronic asthma: reproducibility and relationship with lung function and severity.

BACKGROUND: In some patients chronic asthma results in irreversible airflow obstruction. High resolution computed tomography (HRCT) has been advocated for assessing the structural changes in the asthmatic lung and permits investigation of the relationships between airway wall thickening and clinical parameters in this condition. METHODS: High resolution CT scanning was performed in 49 optimally controlled asthmatic patients and measurements of total airway and lumen diameter were made by two independent radiologists using electronic callipers. Wall area as % total airway cross sectional area (WA%) and wall thickness to airway diameter ratio (T/D) were calculated for all airways clearly visualised with a transverse diameter of more than 1.5 mm, with a mean value derived for each patient. Intra- and inter-observer variability was assessed for scope of agreement in a subgroup of patients. Measurements were related to optimum forced expiratory volume in 1 second (FEV1), forced mid expiratory flow, carbon monoxide gas transfer, two scores of asthma severity, airway inflammation as assessed with induced sputum, and exhaled nitric oxide. RESULTS: Neither observer produced a statistically significant difference between measurements performed on two occasions but there was a significant difference between observers (limits of agreement -2.6 to 6.8 for WA%, p<0.0001). However, mean WA% measured on two occasions differed by no more than 5.4% (limits of agreement -4.0 to 5.4; mean (SD) 0.7 (2.4)). Statistically significant positive associations were observed between both WA% and T/D ratio and asthma severity (r(S)=0.29 and 0.30, respectively, for ATS score), and an inverse association with gas transfer coefficient was observed (r(S)=-0.43 for WA% and r(S)=-0.41 for T/D). No association was identified with FEV1 or airway inflammation. CONCLUSIONS: The airway wall is thickened in more severe asthma and is associated with gas transfer coefficient. This thickening does not relate directly to irreversible airflow obstruction as measured with FEV1.

Becker muscular dystrophy with bundle branch reentry ventricular tachycardia.

This report describes a case of Becker muscular dystrophy presenting with recurrent symptomatic wide complex tachycardia. Electrophysiologic testing demonstrated the mechanism to be bundle branch reentry ventricular tachycardia. It is important to consider this potential mechanism in patients with ventricular arrhythmias who have this particular clinical entity, since radiofrequency catheter ablation can represent a curative treatment.

Ultrasonic assessment of hemidiaphragmatic movement: an indirect method of evaluating mediastinal invasion in non-small cell lung cancer.

This preliminary study aimed to assess the potential value of diaphragmatic ultrasound (DUS) in evaluating phrenic nerve involvement indirectly, in the non-invasive pre-operative staging of mediastinal invasion in non-small cell lung cancer (NSCLC). A prospective study of 30 patients with NSCLC comparing the findings of diaphragmatic ultrasound, chest radiograph, computed tomography (CT) thorax and mediastinoscopy was performed. In all cases adequate quantitiative assessment of hemidiaphragmatic excursion was obtained. There was discordance in four of 30 patients between DUS and chest radiograph. Three of nine patients with extensive mediastinal disease on CT had abnormal DUS, and two of eight patients with indeterminate mediastinal disease on CT had abnormal DUS and were later found to be non-resectable. No abnormal cases of DUS were found in those cases with normal mediastinal CT. There was no clear relationship between the site, size and side of the primary tumour on CT, or its pleural or diaphragmatic contiguity, and hemidiaphragmatic excursion. There was concordance between DUS and mediastinoscopy in 17 of 21 patients. Two patients had normal mediastinoscopy and abnormal DUS but were not resectable at thoracotomy. No patient with abnormal DUS was resectable. DUS may be of potential value in the pre-operative staging of NSCLC and is therefore worthy of further evaluation.

Comparison of ultrasound with fluoroscopy in the assessment of suspected hemidiaphragmatic movement abnormality.

A comparative study of quantitative hemidiaphragmatic ultrasound with fluoroscopy was undertaken in 30 patients referred for investigation of suspected hemidiaphragmatic movement abnormality. The aim of this study was to determine whether assessment with ultrasound or fluoroscopy differed, and which technique appeared more suitable in the investigation of hemidiaphragmatic movement disorder. There were four technical failures using fluoroscopy (13%), compared with none using ultrasound. Using the normal ranges of right to left ratio of maximal excursion (0.5-2.0 for fluoroscopy and 0.5-1.6 for ultrasound) there was concordance in 21 out of 26 (81%) patients. All cases of abnormality on fluoroscopy were seen on ultrasound. Four of the discordant cases had excursions on the lesser side in the normal range on ultrasound suggesting a milder movement abnormality detected by ultrasound than by fluoroscopy. Sniff testing conferred no advantage over quantitative testing. Ultrasound has technical, qualitative and quantitative advantages over fluoroscopy and should be the method of choice in the investigation of suspected hemidiaphragmatic movement abnormality.

Computed tomographic scanning of the lung in patients with allergic bronchopulmonary aspergillosis and in asthmatic patients with a positive skin test to Aspergillus fumigatus.

BACKGROUND: Allergic bronchopulmonary aspergillosis is a disease of asthmatic patients which may follow a protracted course and result in chronic lung damage such as central bronchiectasis. In asthma uncomplicated by allergic bronchopulmonary aspergillosis, in particular in asthmatic patients with immediate hypersensitivity type skin reactions to Aspergillus fumigatus, the incidence of bronchiectasis is uncertain. METHODS: Computed tomographic (CT) scans were performed in 17 asthmatic patients of mean (SE) age 60.1 (2.5) years, FEV1 49.4 (5.8)% predicted with allergic bronchopulmonary aspergillosis (all with current or previous positive precipitins to A fumigatus) and in 11 asthmatic patients of mean (SE) age 49.5 (5.8) years, FEV1 75.5 (6.5)% predicted, skin test positive for A fumigatus, but without the clinical or serological features of allergic bronchopulmonary aspergillosis (non-allergic bronchopulmonary aspergillosis group). RESULTS: Bronchial dilatation was more common in the group with allergic bronchopulmonary aspergillosis, affecting 14 patients compared with two in the non-allergic bronchopulmonary aspergillosis group. Evidence of bronchiectasis was found in 43 of a possible 102 lobes of patients with allergic bronchopulmonary aspergillosis, compared with three of a possible 66 in the non-allergic bronchopulmonary aspergillosis group. Bronchial wall thickening was common to both, affecting 16 and nine patients respectively. Pleural thickening on CT scanning was common in the group with allergic bronchopulmonary aspergillosis, being noted in 14 patients compared with only three in the non-allergic bronchopulmonary aspergillosis group. CONCLUSIONS: Bronchiectasis is common in allergic bronchopulmonary aspergillosis but occurs only occasionally in asthmatic patients with a positive skin test to A fumigatus but without other features of the disease.

Ultrasound assessment of normal hemidiaphragmatic movement: relation to inspiratory volume.

BACKGROUND: Traditionally the radiological assessment of diaphragmatic movement has relied on fluoroscopy. Ultrasound scanning has recently been shown to be a sensitive and reproducible method of assessing hemidiaphragmatic movement in normal subjects. A study was undertaken to examine how movement of the diaphragm measured by ultrasound scanning relates to inspired lung volumes measured by spirometric testing. METHODS: Ultrasound examinations were performed on 14 normal volunteers using a 3.5 MHz sector transducer (Acuson 128). A fixed skin position on each lateral chest wall between the anterior clavicular and midaxillary line was selected symmetrically to obtain a longitudinal plane of each hemidiaphragm including the maximal renal bipolar length, allowing identification of the adjacent posterior aspect of the diaphragm. Craniocaudal excursions of the posterior part of each hemidiaphragm on successive respiratory cycles were recorded on videotape and compared with spirometric measurements recorded simultaneously on a water bath spirometer. Measurements were made in the sitting and supine position and were repeated on a separate occasion (at least two weeks apart) in 10 subjects by the same operator to assess reproducibility. RESULTS: The relation between inspired volume and hemidiaphragmatic movement was found to be linear. The gradient of these observed linear relations (hemidiaphragmatic excursion (mm)/inspired volume (1)) was calculated and their distribution for each hemidiaphragm followed a normal distribution irrespective of position. The 95% confidence limits of the right to left ratio of these gradients in the supine position were 0.53 and 1.7. Change of posture from the supine to the sitting position reduced the gradient. The technique had acceptable reproducibility with coefficients of variation for the supine position of 7.5% and 11.7% for right and left hemidiaphragm respectively. CONCLUSION: Ultrasound scanning is a simple, non-invasive and reproducible means of assessing hemidiaphragmatic movement, yielding quantitative information which relates to inspired lung volumes.

Moricizine-induced proarrhythmia.

Moricizine is a Class I antiarrhythmic drug currently approved for the treatment of life-threatening ventricular arrhythmias. The drug has received significant attention because of its role in the Cardiac Arrhythmia Suppression Trial. Previous data suggested that the agent has a relatively low proarrhythmic potential. This may lead clinicians to use the drug empirically for less significant ventricular arrhythmias. We report a case of life-threatening late proarrhythmia caused by moricizine and comment on our experience with this agent. We feel that this drug has significant proarrhythmic potential and should not be used empirically to treat ventricular ectopy especially in patients with underlying structural heart disease.

Spontaneously acquired fistula from the right coronary artery to the right ventricular cavity.

A 47 year old man developed a fistula from the right ventricular branch of the right coronary artery to the right ventricular cavity in association with distal occlusion of the main trunk of the right coronary artery. There was no clinical or electrocardiographic evidence of acute myocardial infarction.

Unilateral pulmonary vein stenosis.

Unilateral pulmonary vein stenosis is a rare congenital anomaly. A case is described in a girl who first presented at the age of four years with recurring haemoptysis but in whom diagnosis was not established until she was 16 years old. Pulmonary angiography demonstrated a minimally hypoplastic right pulmonary artery, and the laevophase showed normal pulmonary venous return from the left lung, but none from the right. Surgical treatment was necessary because of life threatening haemoptysis, and pneumonectomy was required in the light of the findings at operation.