Quinine and the ABCs of Long QT: A Patient's Misfortune with Arthritis, (Alcoholic) Beverages, and Cramps.

A 91-year-old woman presented to the emergency department by ambulance after her family found her minimally responsive. Telemetry monitoring demonstrated episodes of non-sustained polymorphic ventricular tachycardia (PMVT) associated with significantly prolonged repolarization. Her medical history revealed that she was taking quinine or a derivative in three different forms: hydroxychloroquine, quinine sulfate (for leg cramps), and her gin mixed with tonic water (containing quinine). The present case is illustrative of classic etiologies and findings of acquired long QT syndrome, and serves as an important reminder for providers to take a complete medication history, including use of duplicative and alternative medicines and type of alcohol consumption.

Accuracy of non-ECG-gated computed tomography angiography of the chest in assessment of left-sided cardiac chamber enlargement.

PURPOSE: To determine whether measurement of left ventricular (LV) and left atrial (LA) diameters on nongated computed tomography angiography (CTA) can detect left atrial and left ventricular enlargement (LAE and LVE) with high specificity. MATERIALS AND METHODS: Ninety-nine patients who had undergone both nongated CTA of the chest and echocardiography within 1 week constituted the pilot group. On CTA, LA and LV diameters were measured in the axial plane and on a 3-chamber-view multiplanar reconstruction. These measurements were compared with echocardiography results. Receiver operating characteristic (ROC) curves were then generated to determine optimal cutoff values for diagnosis of LAE and LVE. These thresholds were applied to a validation group (n = 203), and sensitivities and specificities for cutoff values were determined. Simple κ-coefficients were calculated for interobserver agreement. RESULTS: In the pilot group, axial measurements of the LA and LV diameters were superior to multiplanar reconstruction measurements based on areas under the ROC (LV: 0.82 vs. 0.76, LA: 0.87 vs. 0.82). Using the ROC results, cutoff values of 5.5 and 4.5 cm were chosen for LVE and LAE, respectively. These thresholds were applied to the validation group, achieving an average sensitivity and specificity for LAE of 53% [confidence interval (CI): 37%-71% and 94% (89%-97%)], respectively. Average sensitivity and specificity for LVE were 41% (CI: 23%-59%) and 99% (CI: 96%-100%), respectively. Kappa coefficients for diagnosis of LAE and LVE were 0.70 and 0.81, respectively. CONCLUSION: Thresholds for LA and LV diameter on nongated CTA can be chosen to provide specific, but not sensitive, detection of LAE and LVE.