BackgroundDiscordance between small aortic valve area (AVA; < 1.0 cm2) and low mean pressure gradient (MPG; < 40 mm Hg) affects a third of patients with moderate or severe aortic stenosis (AS). We hypothesized that this is largely due to inaccurate echocardiographic measurements of the left ventricular outflow tract area (LVOTarea) and stroke volume alongside inconsistencies in recommended thresholds.MethodsOne hundred thirty-three patients with mild to severe AS and 33 control individuals underwent comprehensive echocardiography and cardiovascular magnetic resonance imaging (MRI). Stroke volume and LVOTarea were calculated using echocardiography and MRI, and the effects on AVA estimation were assessed. The relationship between AVA and MPG measurements was then modelled with nonlinear regression and consistent thresholds for these parameters calculated. Finally the effect of these modified AVA measurements and novel thresholds on the number of patients with small-area low-gradient AS was investigated.ResultsCompared with MRI, echocardiography underestimated LVOTarea (n = 40; −0.7 cm2; 95% confidence interval [CI], −2.6 to 1.3), stroke volumes (−6.5 mL/m2; 95% CI, −28.9 to 16.0) and consequently, AVA (−0.23 cm2; 95% CI, −1.01 to 0.59). Moreover, an AVA of 1.0 cm2 corresponded to MPG of 24 mm Hg based on echocardiographic measurements and 37 mm Hg after correction with MRI-derived stroke volumes. Based on conventional measures, 56 patients had discordant small-area low-gradient AS. Using MRI-derived stroke volumes and the revised thresholds, a 48% reduction in discordance was observed (n = 29).ConclusionsEchocardiography underestimated LVOTarea, stroke volume, and therefore AVA, compared with MRI. The thresholds based on current guidelines were also inconsistent. In combination, these factors explain > 40% of patients with discordant small-area low-gradient AS.
Background
Takotsubo cardiomyopathy (TC) usually manifests as transient apical ballooning of the left ventricle and may mimic acute coronary syndrome. Concomitant right ventricle involvement may occur in about a third of the cases. Recurrence had been observed in up to 10% of TC with variable ventricular involvement. Despite this knowledge, there had been no report of a patient with multiple biventricular TC in the literature to date. In this study, we describe a rare case of a patient who presented twice with biventricular TC.
Case summary
A 52-year-old man with a previous episode of biventricular TC 5 months ago presented to our hospital with a 1 day history of shortness of breath and wheeze. He was treated initially for infective exacerbation of chronic obstructive airway disease. He was eventually intubated following a trial of non-invasive ventilation. He became hypotensive post-intubation and required intensive care support. An inpatient echocardiogram revealed biventricular apical ballooning. Invasive coronary angiogram showed no coronary artery disease. A repeat echocardiogram 14 days post-admission demonstrated full recovery of both ventricles. These findings were consistent with a second biventricular TC. Two months later, he was found deceased in the community seemingly from an unrelated cause.
Discussion
This case describes a middle-aged gentleman who suffered recurrent biventricular TC with no consistent triggers and an unrelated fatal sequel. None of these features were typical, and to our best knowledge had not been reported before. We hypothesize that his recurrent chronic obstructive pulmonary disease exacerbations and various substance misuse might have predisposed him to this unusual presentation.
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