Upload
others
View
8
Download
0
Embed Size (px)
Citation preview
Washington University School of MedicineDigital Commons@Becker
Conference Abstracts and Posters Division of Emergency Medicine/Emergency CareResearch Section
2012
QTc prolongation is associated with hypokalemiaand hypocalcemia in emergency departmentpatientsLucy FranjicWashington University School of Medicine in St. Louis
Stacey HouseWashington University School of Medicine in St. Louis
Irena VitkovitskyWashington University School of Medicine in St. Louis
S. Eliza HalcombWashington University School of Medicine in St. Louis
Follow this and additional works at: http://digitalcommons.wustl.edu/em_conf
This Presentation Paper is brought to you for free and open access by the Division of Emergency Medicine/Emergency Care Research Section atDigital Commons@Becker. It has been accepted for inclusion in Conference Abstracts and Posters by an authorized administrator of DigitalCommons@Becker. For more information, please contact [email protected].
Recommended CitationFranjic, Lucy; House, Stacey L.; Vitkovitsky, Irena; Halcomb, S. Eliza, "QTc prolongation is associated with hypokalemia andhypocalcemia in emergency department patients" (2012). Conference Abstracts and Posters. Paper 12.http://digitalcommons.wustl.edu/em_conf/12
QTc Prolongation is Associated with Hypokalemia and Hypocalcemia in Emergency Department Patients
Stacey L. House MD PhD, Lucy Franjic MD, Irena Vitkovitsky MD, S. Eliza Halcomb MD
Washington University in St. Louis
Division of Emergency Medicine
Lucy Franjic, MD
Society for Academic Emergency Medicine Great Plains Regional Research Forum St. Louis, MO. September 2012 © Stacey House, 2012
Congenital Six types (LQT1-LQT6) Mutations in genes encoding potassium and
sodium transmembrane channel proteins
Acquired Hypokalemia, hypocalcemia, hypomagnesemia, HIV,
myocardial ischemia, numerous medications and drugs (i.e. cocaine)
QTc Prolongation
Increased risk of cardiac arrhythmias Torsades de pointes Ventricular fibrillation Sudden cardiac death
QTc Prolongation
Multiple case reports and small studies in select populations have shown a correlation between electrolyte abnormalities and prolonged QTc interval
Recently Golsari et al evaluated 258 medicine
admit patients and did not find any association between electrolyte abnormalities and QTc interval
Electrolyte Abnormalities and QTc Interval
Retrospective chart review of all ED patients who received an ECG for any reason during the 5 month period of June 2009 – October 2009 at a large volume, tertiary care center.
Inclusion Criteria: Patients with a computer generated QTc ≥ 460 ms.
Exclusion Criteria: Bradycardia (HR < 60 bpm) Tachycardia (HR > 100 bpm) QRS > 120 ms Non-sinus or paced rhythm Patients who left without being seen or against medical advice ED electronic medical records were reviewed for patient demographics, presenting symptoms, comorditities, electrolyte concentrations, medication administration, and disposition. Statistical Analysis - Data is expressed as proportion with 95% confidence intervals. Data was compared among groups using a Chi-squared test.
Methods
2402 pts (20%) QTc ≥ 460 ms
11,359 Patients
8957 pts (80%) Normal QTc
1084 pts (45%) Eligible
1318 pts (55%) Excluded
615 pts (57%) QTc 460-479 ms
274 pts (25%) QTc 480-499 ms
195 pts (18%) QTc 500+ ms
5.4% % of all pts 2.4% 1.7%
Excluded Patients QRS > 120 ms 559 pts Tachycardia 581 pts Bradycardia 151 pts Non-sinus rhythm 239 pts Paced rhythm 182 pts LWBS or AMA 27 pts
RESULTS
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
Chest Pain SOB Lightheaded/dizzy Syncope Ingestion Palpitations Fatigue/weakness Seizure
Prop
ortio
n Pr
esen
t Presenting Symptoms
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
Chest Pain SOB Lightheaded/dizzy Syncope Ingestion Palpitations Fatigue/weakness Seizure
Prop
ortio
n Pr
esen
t
460-479 ms480-499 ms500+ ms
Presenting Symptoms
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Htn DM CHF CAD/MI Pacemaker/AICD Arrhythmia Psych Drug Abuse HIV
Prop
ortio
n Pr
esen
t
Past Medical History
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Htn DM CHF CAD/MI Pacemaker/AICD Arrhythmia Psych Drug Abuse HIV
Prop
ortio
n Pr
esen
t
460-479 ms
480-499 ms
500+ ms
Past Medical History
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
[K] obtained [Mg] obtained [Ca] obtained
Prop
ortio
n Pr
esen
t
460-479 ms
480-499 ms
500+ ms
Electrolytes Obtained
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
Abnormal [K] Hypokalemia Hyperkalemia
Prop
ortio
n Pr
esen
t
460-479 ms
480-499 ms
500+ ms
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
Abnormal [Ca] Hypocalemia Hypercalcemia
Prop
ortio
n Pr
esen
t
460-479 ms
480-499 ms
500+ ms
Electrolyte Abnormalities and association with QTc interval
* *
*
* p<0.01
Electrolyte Repletion
Potassium was repleted in 66 ± 10% of patients with hypokalemia
Calcium was repleted in 13 ± 5% of patients with hypocalcemia
Magnesium supplementation occurred in only to 2 ± 1% of pts
Only 1 ± 0.6% of pts with QTc > 500 ms had magnesium supplementation
CONCLUSIONS QTc prolongation is associated with hypokalemia
and hypocalcemia in ED patients The decision to replete electrolytes in the ED does
not appear to be related to QTc interval ED patients with prolonged QTc infrequently have
Mg determined and rarely receive prophylactic treatment
Further studies necessary to determine effect of electrolyte repletion and magnesium prophylaxisis in prevention of cardiac dysrhythmias in ED patients
El-Sherif, N. "Electrolyte Disorders and Arrhythmogenesis." Journal of Cardiology. 18 (2011): 233-45.
Golzari, H. “Prolonged QTc intervals on admission electrocardiograms: prevalence and correspondence with admission electrolyte abnormalities.” Connecticut Medicine. 7 (2007): 389-97.
Schulman M. “Hypokalemia and cardiovascular disease.” American Journal of Cardiology. 65 (1990): 4E-9E.
Seftchick, Michael. “The prevalence and factors associated with QTc prolongation among emergency department patients.” Annals of Emergency Medicine. 54 (2009). 763-768.
Taylor, D. “Cocaine induced prolongation of the QT interval.” Emergency Medicine Journal. 21 (2004): 252-253.
Thomspon, RG. “Hypokalemia after resuscitation out-of-hospital ventricular fibrillation.” JAMA. 248 (1982): 2860-2863.
BIBLIOGRAPHY