Pregnancy

• August 3, 2016: “The Pregnancy Journey with Inherited Arrhythmia ”

This free webinar, the first of a three-part series, was held on August 3, 2016 and provided a demonstration of fetal and maternal care during pregnancies affected with long QT syndrome. This webinar also illustrated the psychosocial experience of a pregnancy affected by long QT syndrome through detailed experiences from a patient and examine the perspective of a genetic counselor working with prenatal patients with inherited arrhythmias.

 To view the webinar, click here.

RESEARCH-Currently Enrolling Studies:

• Study of pregnancy and LQTS; you can participate from anywhere in the world. Dr. Bettina Cuneo, a pediatric cardiologist who specializes in fetal echocardiography has spent many years devoted to researching pregnancy and LQTS.
  

• Role of fetal magnetocardiography (FMCG) in diagnosing LQTS during pregnancy; NIH-funded study at the University of Wisconsin. Looking for families with history of LQTS, and fetuses with an unexplained slow heart rate, ventricular tachycardia, or AV block. Limited funds may be available for travel. For more information about the study, CLICK HERE

Read our story about one woman’s experience with diagnosing LQTS in utero using fMCG CLICK HERE.

PREVIOUS RESEARCH:

Long QT Syndrome-Gender Associated Symptoms and Frequency of Cardiac Events During Pregnancy and the Post-Partum Period

Studies show there are significant gender differences in genotyped LQTS patients relative to age of first episode, syncope, cardiac arrest and sudden death.  According to Emanuela H. Locati et.al. in the paper, “Age and Sex-Related Differences in Clinical Manifestations in Patients with Congenital Long-QT Syndrome”, males have a higher risk of cardiac events (meaning syncope or blackout spells, cardiac arrest and sudden death) during childhood (with an average earlier age of onset in males at 8 years old vs.14 years in females), through puberty.  Studies reveal females have an increased risk relative to males during adulthood.  Where sudden death occurred, males died on average at 13 years whereas females at 20 years.  Males had a 32 % incidence of sudden death as a first episode in comparison to 9% in women.  Studies showed that among referred subjects to the LQTS Registry, “only a few males had a first cardiac event after 15 years of age whereas about half of the females had a first cardiac event after 15 years of age.”  (1)

The paper by Eric J. Rashba, et.al., “Influence of Pregnancy on Risk for Cardiac Events in Patients with Hereditary Long -QT Syndrome”, reviews the findings of a retrospective study of 422 LQTS women, (111 probands or first identified family member with LQTS and 311 first degree female relatives) who have experienced at least one or more pregnancies.   Symptom information on these subjects was reviewed for the 40-week pregnancy period plus the 40 weeks prior to pregnancy and the 40 weeks post pregnancy or post-partum period.  Analysis showed of the 111 probands, 26 (23.4%) had cardiac events during the post-partum period, with 10 (9%) during pregnancy and 4 (2.8%) in the pre-pregnancy period.  (Only 2 patients had cardiac events during delivery with the remaining 24 experiencing events during the 40 weeks post-partum.) (2)

Thus, this study implicates that probands were at a significant risk for cardiac events during the post-partum period; additionally nearly 10% having a first cardiac event during this time frame.  However, Beta-blocker treatment was also noted to associate with meaningful reduction of risk for cardiac events among probands.  Also mentioned was that Beta-blockers studied extensively in hypertensive patients during pregnancy noted that maternal treatment with specifically “propranolol was infrequently associated with neonatal bradycardia, respiratory depression, hypoglycemia and intrauterine growth retardation in several small, uncontrolled studies….fetal malformations post maternal treatments with (propranolol, atenolol and metoprolol) were not observed.”  (2; for further reading refer to referenced articles in this manuscript on Beta-blocker treatment.)

In over 10 years of personal retrospective communications with LQTS patients and family members regarding cardiac events during the post-partum period, (in general, cardiac arrests and/or sudden deaths occurred prior to LQT diagnosis and thus most women were not on Beta-blocking medications), several commonalities have been noted:

1. All patients had their events in association with severe anxiety, illness, sleep deprivation, baby blues or depression.  (Sleep deprivation being the most common or in combination with one or more previously named precipitators.)
2. Loud and/or unexpected noise—alarm clock, or sudden arousal from sleep.
3. Inattention to proper diet, poor eating habits or extreme weight loss.
4. Vigorous or excessive exercise.
5. Over the counter medications (particularly weight reducing aids) which were later discovered to prolong the QT-interval or alter blood electrolyte concentrations.

Suggestions for the 40-week post-partum period and beyond:

1. Maintain strict compliance with prescribed Beta-blocker medications. (3, 4)
2. Avoid all drugs or medications implicated to cause further prolongation of the QT-interval.
3. Adhere to a healthy diet.

   a. Increase dietary intake of potassium rich foods.

   b. Reduce consumption of sugary rich foods.

   c. Precautionary avoidance of drinks and foods containing caffeine and/or alcohol are suggested (some clinical studies suggest a pro-arrhythmia effect with excessive ingestion of caffeine and alcohol).

   d. Avoid grapefruit, grapefruit juices and Green Tea (the flavonoid contained in the chemical make-up of grapefruit and green tea is known to specifically inhibit function of the cardiac HERG ion channel when consumed in large volumes). (5,6)

   e. Consider the addition of omega-3 oils to diet. (7-9)

4. Get plenty of rest.
5. Exercise sensibly and with caution.
6. Remove all alarm clocks or telephones from resting areas. (3)
7. Reduce as much as possible, stress and anxiety.
8. Seek help to relieve problems of depression, but be cautious in taking prescribed medications for depression.

Submitted by: Katherine Timothy Clinical Coordinator of Cardiac Arrhythmia Genetic Research Mark T. Keating Genetic Laboratory
University of Utah and Harvard University

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