Management of the thyroid gland with laryngectomy for cT3 glottic carcinomas

Is routine hemithyroidectomy justified in laryngectomy for laryngeal carcinoma? Hemithyroidectomy with laryngectomy causes hypothyroidism in up to 25% of patients, and if combined with radiotherapy, in up to 70%. ^3,8,9,10 In this review of 102 total laryngectomies with routine hemithyroidectomy for cT3 glottic carcinoma, laryngeal carcinoma involved the thyroid gland in two. Both had subglottic tumour extension. The tumour approached within 3 mm of the thyroid capsule in seven. It is proposed that thyroidectomy should be performed only in selected laryngeal carcinomas. Intraoperative assessment of the thyroid gland should determine the need for thyroidectomy in glottic and transglottic carcinomas. Carcinoma invasion of the thyroid gland should be confirmed by frozen section before proceeding to thyroidectomy. In the absence of thyroid gland involvement, both thyroid lobes may be preserved. Total thyroidectomy should be performed if the thyroid gland has been invaded. Total thyroidectomy should be routinely performed with subglottic carcinomas.     

Search for the Optimal Right Ventricular Pacing Site: Design and Implementation of Three Randomized Multicenter Clinical Trials

Background: The optimal site to permanently pace the right ventricle (RV) has yet to be determined. To address this issue, three randomized prospective multicenter clinical trials are in progress comparing the long-term effects of RV apical versus septal pacing on left ventricular (LV) function. The three trials are Optimize RV Selective Site Pacing Clinical Trial (Optimize RV), Right Ventricular Apical and High Septal Pacing to Preserve Left Ventricular Function (Protect Pace), and Right Ventricular Apical versus Septal Pacing (RASP).
Methods: Patients that require frequent or continuous ventricular pacing are randomized to RV apical or septal pacing. Optimize RV excludes patients with LV ejection fraction <40% prior to implantation, whereas the other trials include patients regardless of baseline LV systolic function. The RV septal lead is positioned in the mid-septum in Optimize RV, the high septum in Protect Pace, and the mid-septal inflow tract in RASP. Lead position is confirmed by fluoroscopy in two planes and adjudicated by a blinded panel. The combined trials will follow approximately 800 patients for up to 3 years.
Results: The primary outcome in each trial is LV ejection fraction evaluated by radionuclide ventriculography or echocardiography. Secondary outcomes include echo-based measurements of ventricular/atrial remodeling, 6-minute hall walk distance, brain natriuretic peptide levels, and clinical events (atrial tachyarrhythmias, heart failure, stroke, or death).
Conclusion: These selective site ventricular pacing trials should provide evidence of the importance of RV pacing site in the long-term preservation of LV function in patients that require ventricular pacing and help to clarify the optimal RV pacing site.     

Tachycardia Recognition and Diagnosis from Changes in Right Atrial Pressure Waveform—A Feasibility Study

Implantable defibrillators either monitor heart rate or use a probability density function to detect ventricular fibrillation/tachycardia. As a result, they are unable to discriminate sinus tachycardia and atrial arrhythmias from malignant ventricular rhythms. We have assessed high fidelity fiber-optic pressure recordings in the right atrium during cardiac arrhythmias in 23 patients (mean age 44 years, 11 females) undergoing electrophysiological study. The unfiltered pressure signal was amplified and recorded on paper. During sinus rhythm, a constant amplitude deflection occurred during atrial systole (a wave). A characteristic waveform pattern was observed during each of the studied tachyarrhythmias, which included atrial flutter and fibrillation, atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia, and ventricular tachycardia with and without ventriculoatrial conduction. The waveform pattern allowed clear visual discrimination of the underlying arrhythmia. Mean atrial pressure was increased during all arrhythmias and did not allow discrimination of the nature of the tachycardia. High fidelity pressure recordings produced characteristic appearances for pattern recognition of each arrhythmia studied. They allowed determination of the temporal relation between electrical and mechanical cardiac events and may have potential in the detection and recognition of cardiac arrhythmias.