High prevalence of respiratory ciliary dysfunction in congenital heart disease patients with heterotaxy.

BACKGROUND: Patients with congenital heart disease (CHD) and heterotaxy show high postsurgical morbidity/mortality, with some developing respiratory complications. Although this finding is often attributed to the CHD, airway clearance and left-right patterning both require motile cilia function. Thus, airway ciliary dysfunction (CD) similar to that of primary ciliary dyskinesia (PCD) may contribute to increased respiratory complications in heterotaxy patients. METHODS AND RESULTS: We assessed 43 CHD patients with heterotaxy for airway CD. Videomicrocopy was used to examine ciliary motion in nasal tissue, and nasal nitric oxide (nNO) was measured; nNO level is typically low with PCD. Eighteen patients exhibited CD characterized by abnormal ciliary motion and nNO levels below or near the PCD cutoff values. Patients with CD aged >6 years show increased respiratory symptoms similar to those seen in PCD. Sequencing of all 14 known PCD genes in 13 heterotaxy patients with CD, 12 without CD, 10 PCD disease controls, and 13 healthy controls yielded 0.769, 0.417, 1.0, and 0.077 novel variants per patient, respectively. One heterotaxy patient with CD had the PCD causing DNAI1 founder mutation. Another with hyperkinetic ciliary beat had 2 mutations in DNAH11, the only PCD gene known to cause hyperkinetic beat. Among PCD patients, 2 had known PCD causing CCDC39 and CCDC40 mutations. CONCLUSIONS: Our studies show that CHD patients with heterotaxy have substantial risk for CD and increased respiratory disease. Heterotaxy patients with CD were enriched for mutations in PCD genes. Future studies are needed to assess the potential benefit of prescreening and prophylactically treating heterotaxy patients for CD.

Profound hypokalemia: unusual presentation and management in a 12-year-old boy.

Hypokalemia is a frequent electrolyte abnormality that rarely requires more than oral supplementation to correct. We describe a case of profound hypokalemia and cardiac arrhythmia requiring unusually large amounts of "bolused" potassium to restore to normal sinus rhythm. Our patient presented with significant dehydration and electrolyte abnormalities after several days of emesis. Most alarming of these findings was a serum potassium level of 1.2 mEq/L. The electrocardiogram showed changes consistent with hypokalemia that rapidly degraded into pulseless ventricular tachycardia. Potassium chloride of 140 mEq was hand-pushed during the resuscitation with return of spontaneous rhythm. The patient was discharge 11 days later in his prearrest state.

Increased postoperative respiratory complications in heterotaxy congenital heart disease patients with respiratory ciliary dysfunction.

OBJECTIVE(S): Congenital heart disease (CHD) and heterotaxy patients have increased postoperative and respiratory complications. We recently showed CHD-heterotaxy patients can have respiratory ciliary dysfunction (CD) similar to that associated with primary ciliary dyskinesia, including low nasal nitric oxide and abnormal ciliary motion. In this study, we investigated whether CHD-heterotaxy patients with CD may have worse postsurgical outcomes. METHODS: We examined postsurgical outcome in 13 heterotaxy-CHD patients with CD (25 surgeries), compared with 14 heterotaxy-CHD patients without CD (27 surgeries). Outcome data were collected for each surgery, including respiratory complications, tracheostomy, use of inhaled ß-agonists or nitric oxide, length of hospital stay, days on ventilator, and death. RESULTS: The CD versus the no-CD CHD cohorts had similar Risk Adjustment in Congenital Heart Surgery-1 risk categories, repair track, age at surgery, and follow-up evaluation times. Respiratory complications (76% vs 37%; P = .006), need for tracheostomy (16% vs 0%; P = .047), and use of inhaled ß-agonists (64% vs 11%; P = .0001) all were increased significantly in heterotaxy-CHD patients with CD. No significant differences were detected in postoperative hospital stay, days on mechanical ventilation, or surgical mortality. A trend toward increased mortality for the CD group beyond the postoperative period was observed (33% vs 0%; P = .055) in patients younger than age 10 years. CONCLUSIONS: Our findings showed that heterotaxy-CHD patients with CD may have increased risks for respiratory deficiencies. Overall, there was a trend toward increased mortality in CD patients with intermediate follow-up evaluation. Because ß-agonists are known to increase ciliary beat frequency, presurgical screening for CD and perioperative treatment of CD patients with inhaled ß-agonists may improve postoperative outcomes and survival.