ECG abnormalities progress during pulmonary arterial hypertension course
medwireNews: Researchers have identified a number of electrocardiography (ECG) variables that progress between diagnosis and death in patients with pulmonary arterial hypertension (PAH).
Their study “suggests potential new ECG predictors of outcome that deserve further investigation,” say Adriano Tonelli and colleagues, from the Cleveland Clinic in Ohio, USA.
There were 50 patients in the study, 39 of whom had an ECG at the time of diagnosis. ECG is not recommended for PAH diagnosis, and, indeed, 7.7% of these patients had normal findings. But none of the patients had normal ECG findings close to the time of death (median of 0 months before).
The patients were aged an average of 58 years, and died a median of 40 months after PAH diagnosis, with 42% dying as a direct result of PAH (right heart failure or sudden death).
There were a number of changes on ECG between diagnosis and close to death: 11 in all. The most statistically significant of these included heart rate, which rose from an average of 83 to 89 beats per minute; QRS frontal axis, which increased from 97 to 112 degrees; R wave amplitude in D1, which declined from 0.46 to 0.30 mV; an R to S amplitude ratio of at least 1.0 in lead V1, rates of which rose from 48.7% to 74.0%; and a negative T wave in the inferior leads, rates of which rose from 30.8% to 60.0%.
ECGs performed between diagnosis and death, at a median of 27 months before death, gave intermediate results for most of these parameters, showing a general progression over time, the team reports in the Annals of Noninvasive Electrocardiology.
Progression of right ventricular hypertrophy between diagnosis and death varied according to the criteria used. For example, it increased significantly from 85% to 100% according to the Butler criteria, but did not significantly increase (85% to 88%) according to the World Health Organization criteria.
ECG findings close to death were similar for patients who died of PAH and those who died of other causes, except for a higher rate of right ventricular hypertrophy, by two definitions, and larger R waves in the V2 lead among those who died of PAH.
“Alone or in combination, these electrocardiographic parameters need further evaluation to identify whether they can be useful biomarkers of poor prognosis in PAH,” conclude the researchers.
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By Eleanor McDermid, Senior medwireNews Reporter