Cardiac Issues in Congenital Central Hypoventilation Syndrome (CCHS)

Cardiac Issues in Congenital Central Hypoventilation Syndrome (CCHS)

(Summary as it relates to Wyatt, 20/33 PHOX2B genotype/mutation)

·         Abstracts from 2008 study on 20/25, 20/26 and 20/27 PHOX2B genotype/mutation http://www.cchsnetwork.org/images/stories/PDF/literature/CCHS_Cardiac_Issues.pdf

 

“Minimum heart rate varied by genotype (w2 2df ¼ 6:89, P¼0.03), with lowest values obtained for the subjects with the 20/27 genotype (genotype 20/25 vs. 20/27 comparison P¼0.02, 20/25 vs. 20/26: P¼0.07, 20/26 vs. 20/27: P¼0.2).”

 

“The longest r-r interval was found to be independent of the baseline heart rate as well as the time of day.”

 

“Though longest QTc interval did not vary by genotype, all children with CCHS had at least one Holter with a QTc interval above 450 msec, and the percent of QTc above 450 msec was substantial considering the overall rarity of QTc greater than 440 msec in normal children.”

 

“Though some children may demonstrate staring spells or syncope at the time of the transient asystole, most subjects are asymptomatic. This underlying propensity for prolonged r-r interval may increase the vulnerability of the child with CCHS when exposed to pharmacologic agents or anesthesia.”

 

“The reticence to implant a cardiac pacemaker may be the result of uncertainty as to the clinical significance of prolonged r-r intervals in the seemingly asymptomatic subject, particularly if subsequent r-r intervals are shorter than 3 sec. Because the impact of prolonged sinus pauses on long term neurodevelopment is unknown, and because childhood is such a critical period for neurocognitive development coupled with the overriding risk for sudden death, recommendation for implantation of a cardiac pacemaker in the child with CCHS and r-r intervals of 3 sec or longer seems to be the most conservative recommendation.”

 

·         Abstracts from the 2010 American Thoracic Society, Clinical Policy Statement: Congenital Central Hypoventilation Syndrome http://www.cchsnetwork.org/images/stories/PDF/literature/CCHS-ATS.pdf

 

“Cardiac rhythm abnormalities, including decreased beat-to-beat heart rate variability, reduced respiratory sinus arrhythmia, and transient abrupt asystoles, have been described (9, 101, 102). Seventy-two–hour Holter monitoring performed annually may determine aberrant cardiac rhythms, sinus pauses that will necessitate bipolar cardiac pacemaker implantation (103), and the frequency of shorter pauses (i.e., less than 3 s) that may have physiologic and neurocognitive impact.”

 

·         Statement on Cardiac Pacing in CCHS written by Dr. Tom Keens

http://www.cchsnetwork.org/images/stories/PDF/literature/cchs%20cardiac%20pacing%20keens%203_13.pdf