What do you *really* need to do with your SVT patients? Well, this is a retrospective observational study of 633 consecutive SVT patients over 10 years seen in a single ED. This was more hypothesis generating than anything – they basically provide patient characteristics and try to tease out if labs / imaging were necessary.
Their mean age was 55, 62% of patients were female, 55% had prior SVT history, 31% had at least one cardiovascular risk factors (dyslipidemia, hypertension, diabetes, CHF, or vascular disease), and 9% had ischemic heart disease.
Some interesting lab nuggets:
-0.4% had a hemoglobin < 8g/L
-1.5% had a sodium >150 mmol/L, none <126
-no patient with severe hyperthyroidism
Chest Xray was obtained 30% of the time, and while it was abnormal 21.6% of the time (41 of 190), none of the time did it alter ED treatment – despite showing 14 cases of pulmonary edema, 4 cases of pneumonia, and 3 pleural effusions.
The authors conclude that patients with uncomplicated SVT are over-investigated, and that most have normal or near-normal results. While I tend to agree – for the 25 year old in SVT without a concerning story – the 55 year old diaphoretic (14% were diaphoretic) female with ischemic heart disease I’m going to work up. Chest films were only ordered on 30% of these patients – frankly in a US hospital, I’m thankful its not higher.
I know Billy Mallon loves his TSH, but why not get a better history to see if there are other concerning symptoms before sending off TSH… Speaking of which, maybe we could decrease those Chest films if we fixed the patient a bit, then reassessed to see if imaging is wanted. (ie, are you still short of breath?).
Finally, I think this study is plagued by premature closure, as they only searched for cases with a discharge diagnosis of paroxysmal supraventricular tachycardia. They’re likely missing at least a few patients who came in with SVT and were found to have actually have another diagnosis.
Ultimately, while this study should not change practice by any means, it should give us pause before shotgunning labs & chest films until after we treat the patient, re-evaluate, and get a better history. This could probably be said for many other diagnoses besides SVT.