Right atrial dysfunction is associated with atrial arrhythmias in adults with repaired tetralogy of fallot

BACKGROUND

Adults with repaired tetralogy of Fallot (TOF) have right atrial (RA) remodeling and dysfunction, and RA function can be measured using speckle tracking echocardiography. There are limited data about the role of RA strain imaging for risk stratification in this population. We hypothesized that RA reservoir strain can identify TOF patients at risk of developing atrial arrhythmia. To test this hypothesis, we assessed the relationship between RA reservoir strain and atrial arrhythmias in adults with repaired TOF.

METHOD

Retrospective cohort study of adults with repaired TOF, and no prior history of atrial arrhythmias. Atrial arrhythmia was defined as atrial fibrillation, atrial flutter/atrial tachycardia, and categorized as new-onset versus recurrent atrial arrhythmias.

RESULTS

We identified 426 patients (age 33 ± 12 years; males 208 (49%)) that met the inclusion criteria. The mean RA reservoir strain, conduit strain, and booster strain were 34 ± 11%, 20 ± 9%, and 15 ± 12%, respectively. Of 426 patients, 73 (17%) developed new-onset atrial arrhythmias (atrial flutter/tachycardia n = 42; atrial fibrillation n = 31); annual incidence 1.9%. RA reservoir strain was associated with new-onset atrial arrhythmias (adjusted HR 0.95, 95% CI 0.93-0.97) after multivariable adjustment. Of 73 patients with new-onset atrial arrhythmia, 41 (56%) had recurrent atrial arrhythmia (atrial flutter/tachycardia n = 18; atrial fibrillation n = 23); annual incidence 11.2%. Similarly, RA reservoir strain was associated with recurrent atrial arrhythmias (adjusted HR 0.92, 95% CI 0.88-0.96) after multivariable adjustment.

CONCLUSIONS

RA strain indices can identify patients at risk for atrial arrhythmias, and this can in turn, be used to guide the type/intensity of therapy in such patients.

Prognostic Performance of Right Ventricular Global Longitudinal Strain Measurements in Patients With Ebstein Anomaly

BACKGROUND

There are limited data on the prognostic role of right ventricular global longitudinal strain (RVGLS) in patients with Ebstein anomaly.

OBJECTIVES

This study sought to assess the relationship between RVGLS and mortality and to compare prognostic performance of RVGLS with conventional echocardiographic indices of right ventricular (RV) systolic function.

METHODS

This study identified adults with Ebstein anomaly with echocardiographic assessment of RV systolic function (RVGLS, RV fractional area change [RVFAC], RV tissue Doppler systolic velocity [RV s'], and tricuspid annular plane systolic excursion [TAPSE]) from 2003 to 2020. For ease of presentation, RVGLS was modeled as absolute values (ie, without the negative sign).

RESULTS

Of 620 patients (median age 37 years; men 261 [42%]), the mean absolute RVGLS, RVFAC, RV s', and TAPSE were 18% ± 5%, 32% ± 9%, 14 ± 6 cm/s, and 22 ± 8 mm, respectively. There were correlations between absolute RVGLS and RVFAC (r = 0.71; P < 0.001), between absolute RVGLS and RV s' (r = 0.41; P = 0.03), and between absolute RVGLS and TAPSE (r = 0.44; P = 0.002). Of 620 patients, 47 (8%) died during follow-up, and 34 of these deaths were cardiovascular. Absolute RVGLS was independently associated with all-cause mortality (adjusted HR: 0.94; 95% CI: 0.92-0.96 per unit increase) and cardiovascular mortality (adjusted HR: 0.92; 95% CI: 0.90-0.94 per unit increase). Absolute RVGLS had superior prognostic power (ie, ability to predict mortality) as compared with RVFAC, RV s', or TAPSE.

CONCLUSIONS

These data support the use of RVGLS for risk stratification in Ebstein anomaly, and further studies are required to assess how interventions may affect different patients according to risk stratification.

Induction of lactation by two techniques: success rate, milk composition, estrogen and progesterone in serum and milk, and ovarian effects

Induction of lactation was attempted in 12 heifers and 12 cows with estradiol benzoate (.011 mg/kg body weight per day) subcutaneous for 10 days or that plus progesterone (.1 mg + .25 mg/kg body weight per day) for 7 days. Milking commenced on day 20 for those treated with the mixture and on day 11 for the others. Lactations were induced (minimum of 4.5 kg of milk/day) in five of six heifers and two of six cows by the mixture and in six of six heifers and three of six cows for estradiol benzoate. Milk production was 44% of herdmates in the 16 induced lactations. Cows on the single treatment had lower production than the other three groups. Ovarian status, cycling, cystic, or static, was affected adversely in 5 of 16 animals induced successfully. Two of the 16, both heifers, carried calves to term following induction. The transition to normal composition of milk was slower for single than double treatment. Lactose increased slowly to normal over the 1st wk of milking while protein decreased slowly. Estrogen and progesterone in milk of induced cows were approximately twice as concentrated as in normal postparturient cows, probably because milk production was halved.