Jonathan S. Zipursky

A rare presentation of an ancient disease: scurvy presenting as orthostatic hypotension

A 49-year-old man presented to hospital with severe orthostatic hypotension, gingival dysplasia and a purpuric rash involving his extremities. The orthostatic hypotension failed to respond to fluids and, on the basis of physical examination and dietary history, the patient was given a preliminary diagnosis of scurvy (ascorbic acid deficiency). Serum ascorbic acid levels were undetectable and the orthostasis was resolved within 24 h of ascorbic acid replacement. The pathogenesis of orthostatic hypotension in the setting of scurvy appears to involve impaired catecholamine synthesis and attenuated vasomotor response to α-adrenergic stimulation. We believe that this case describes a rare presentation of scurvy and highlights a previously under-reported connection between scurvy and vasomotor instability.

Lipophilic β-blockers and Suicide in the Elderly

To the Editorsβ-Adrenergic blockers (β-blockers) are among the most widely prescribed drugs in the world, with more than 191 million prescriptions dispensed in the United States in 2010 alone.1 They are commonly used to manage hypertension, heart failure, and arrhythmias and for the secondary preven

The association of QRS duration with atrial fibrillation in a heart failure with preserved ejection fraction population: a pilot study

Heart failure is a significant cause of morbidity and mortality, yet patient risk stratification may be difficult. Prevention or treatment of atrial fibrillation (AF) may be an important strategy in these patients that could positively affect their outcome. It has been demonstrated that in patients with systolic dysfunction, prolonged QRS duration (QRSd), an easily measured electrocardiographic parameter, is associated with AF.

Maternal infection can cause spontaneous abortion

In their CMAJ article, Muanda and colleagues[1][1] found that exposure to antibiotics during pregnancy was associated with an increased risk of spontaneous abortion. A key question is whether this association is causal or not. We believe the study findings are suggestive of confounding by indication

Non-sustained wide complex tachycardia: an underappreciated sign to aid in diagnosis

AIMS The electrocardiographic (ECG) signs used to differentiate ventricular tachycardia (VT) from supraventricular tachycardia (SVT) with aberrancy are specific but not highly sensitive. The purpose of this study was to define the utility of an underappreciated form of atrioventricular (AV) dissociation at the onset of tachycardia, a single dissociated P wave, in the differentiation of non-sustained monomorphic wide complex tachycardia (WCT) in hospitalized patients. METHODS AND RESULTS We prospectively analysed tracings from 102 consecutive hospitalized patients who had an episode of non-sustained (≥5 beats, <30 s), monomorphic, WCT (≥100 b.p.m.) on telemetry. WCT was classified as VT, SVT with aberrancy, or undifferentiated WCT based on predefined criteria. Of 102 patients with WCT, 3 (3%) had SVT with aberrancy, 43 (42%) had an undifferentiated WCT, and 56 (55%) had VT. ECG evidence of a single dissociated P wave at the onset of tachycardia (i.e. AV dissociation at the onset) was identified in 29 patients (28%) compared with less frequent traditional signs of VT including second-degree ventriculoatrial (VA) block in 18 patients (18%), AV dissociation during tachycardia in 17 patients (17%), fusion beats in 10 patients (10%), and capture beats in 3 patients (3%). On multivariate analysis, only the prematurity index predicted the occurrence of AV dissociation at the onset of the tachycardia (odds ratio 1.239, 95% confidence interval 1.033-1.486, P = 0.021). CONCLUSION When evaluating WCT in hospitalized patients, a single dissociated P wave at the onset of tachycardia is an easily recognizable diagnostic sign of VT, and is observed more frequently than the other accepted criteria for VT.

A colonoscopy preparation gone wrong: propylene glycol mistaken for polyethylene glycol

Propylene glycol is a solvent used commonly in industry and as a diluent in pharmaceuticals [1].. To avoid toxicity, the maximum allowable intake is 25 mg/kg per day [1]. In contrast, polyethylene ...

Comment on Shively et al. “Acute salicylate poisoning: risk factors for severe outcome”

The analysis by Shively et al. [1] regarding predictors of severe outcome in acute salicylate poisoning violates a fundamental principal of statistics. By fitting a logistic regression model with seven variables (salicylate concentration, age, sex, lactate, coingestions, respiratory rate, and coma) to a dataset of 48 subjects (only 10 of whom met the definition of severe toxicity), the resulting regression coefficients are necessarily biased. While the direction and magnitude of the resulting error is unknowable, the adjusted odds ratios presented in Table 3 are almost certainly invalid. Overfitting of this sort is not uncovered by routine diagnostics such as the unadjusted R presented by the authors, and the absence of multicollinearity does not address this concern (although it would, if present, exacerbate the problem). In general, a minimum of 10 events per variable (EPV) is recommended when constructing regression models [2]. Although this rule of thumb may be relaxed in some instances [3], Shively et al. employed a model that is simply too complex for their dataset. As a result, the adjusted analysis cannot be interpreted with confidence. Disclosure statement

Muscle fasciculation detected by ECG

A 79-year-old man presented to hospital with scald burns to the perineum after a syncopal episode while in a hot bathtub. Admission ECG was misdiagnosed as possible ventricular fibrillation with high-frequency irregular waveforms in lead V2 at a rate exceeding 1000 cycles per minute, corresponding to intervening skeletal muscle contractions unrelated to the heart. Follow-up ECG showed full resolution of the irregular waveforms. Muscle fasciculations are a benign cause of ECG artefact and can easily be mistaken for serious cardiac arrhythmias. While most muscle fasciculations detected on ECG are benign, in the correct clinical circumstance these waveforms indicate an underlying neuromuscular disorder. The patient underwent surgical skin grafting with no perioperative cardiac complications and no further syncope in hospital.

Severe gastroparesis after catheter ablation for atrial fibrillation

A 65-year-old woman presented to hospital following 10 days of vomiting, epigastric pain, abdominal bloating and decreased bowel movements. She had a history of peptic ulcer disease and atrial fibrillation. Her medications were amiodarone, rivaroxaban and omeprazole. Ten days prior, she had