In patients with hyperthyroidism and normal LV systolic function, up to 47% had PHT due to either PAH with increased CO (70%) or PVH with elevated LV filling pressure (30%). Most importantly, hyperthyroidism-related PHT was largely asymptomatic and reversible after restoration to a euthyroid state.

Ventricular tachyarrhythmias may occur during intravenous arsenic trioxide (As 2 O 3 ). This has not happened during oral As 2 O 3 . Sixteen patients were studied by electrocardiography and 24-hour Holter monitoring at baseline, during and after oral As 2 O 3 (As 2 O 3 -ON, As 2 O 3 -OFF). QT and corrected QT (QTc) were significantly longer during As 2 O 3 -ON than in As 2 O 3 -OFF, but QT and QTc dispersions were comparable. The patients' 24-hour heart rates were higher during As 2 O 3 -ON than in As 2 O 3 -OFF. QTc intervals at each hour were longer during As 2 O 3 -ON than in As 2 O 3 -OFF. However, QTc prolongation of more than 30 milliseconds only occurred at one time point (2 hours) after oral As 2 O 3 , resulting in QTc of more than 500 milliseconds in 3 of 16 patients, all within 4 hours of oral As 2 O 3 . Although the standard deviation of normal RR interval was lower during As 2 O 3 -ON, ratios of low frequency to high frequency power for As 2 O 3 -ON and As 2 O 3 -OFF were comparable. No ventricular proarrhythmias were observed. These observations, due to the lower peak plasma arsenic reached during oral IntroductionArsenic trioxide (As 2 O 3 ) is efficacious in acute promyelocytic leukemia (APL). 1-4 It blocks potassium currents I Kr and I Ks , 5 causing QT prolongation. Ventricular tachyarrhythmias were reported in about 30% of patients treated with intravenous As 2 O 3 . [6][7][8][9] As 2 O 3 may be effective in other neoplasms, 10 making clinical trials of As 2 O 3 in these diseases pressing. However, reliance on intravenous As 2 O 3 hampers these efforts. Long-term intravenous As 2 O 3 is resource-demanding. Moreover, a potentially fatal cardiac toxicity is worrisome, especially in clinical trials.We have developed an oral formulation of As 2 O 3 . 4,11 Details of the preparation and pharmacokinetics of oral As 2 O 3 have been previously reported. 11 Oral As 2 O 3 gives a similar bioavailability, but lower peak plasma arsenic concentrations, as compared with intravenous As 2 O 3 . 11 Oral As 2 O 3 represents an advance in arsenic therapy. Patients take oral As 2 O 3 at home, rendering long-term therapy feasible, thus facilitating clinical trials. Most importantly, in more than 600 patient weeks of oral As 2 O 3 administered during 5 years, no ventricular tachyarrhythmias were observed. 4,11 Prolongation of QT or corrected QT (QTc) increases the risks of ventricular tachyarrhythmias. 12,13 QT-interval dispersion measures regional nonhomogeneities of ventricular repolarization. 14 Greater dispersions increase ventricular arrhythmias. 15 Heart rate variability (HRV) measures the beat-to-beat heart rate variations, correlating with changes in autonomic tone. HRV changes increase cardiac arrhythmias. 16 To explain the favorable cardiac side-effect profile of oral As 2 O 3 , we studied a cohort of patients on long-term oral As 2 O 3 , to determine the cardiac safety and changes of QT intervals and HVR. Study design PatientsWe studied 17 consecutive patients with relapsed APL (Table 1). All had normal ...

USCOM device operated by trained nurse can provide a simple, accurate, and fast non-invasive method for the AVI optimization in CRT population.