Epinephrine Test in a Patient with Aquired Long QT Syndrome

Vorlage, Beispiel , 2017 , 9 Seiten , Note: 10

Gesundheit - Sonstiges

We report a case of aquired long QT syndrome after Ceftazidime. The patient presented 10 episodes of torsades des points with syncope or cardiac arrest necessitating intubation and mechanical ventilation. After stopping the antibiotic the QT interval normalized. We performed an epinephrine test for concealed long QT and there was a decrease of the QT interval with low dose adrenaline and further decrease with high dose adrenaline. The patient was implanted with a unicameral defibrillator.

EPINEPHRINE TEST IN A PATIENT WITH AQUIRED LONG QT SYNDROME

We report a case of aquired long QT syndrome after Ceftazidime. The patient presented 10 episodes of torsades des points wi

th syncope or cardiac arrest necessitating intubation and mechanical ventilation. After stopping the antibiotic the QT interval normalized. We performed an epinephrine test for concealed long QT and there was a decrease of the QT interval with low dose adrenaline and further decrease with high dose adrenaline. The patient was implanted with a unicameral defibrillator

DESCRIPTION:

A 62 year old female was hospitalized for repetitive episodes of polymorphic ventricular tachycardia and ventricular fibrillation (10 episodes) after treatment with ceftazidime. ECG showed long QT interval of 660 msec that normalized after interruption of ceftazidime. She was transferred to our department for electrohysiological study. At arrival she had normal QT interval of 380 msec. T wave was negative in the precordial leads but coronarography was normal. We proposed an adrenaline test for congenital QT syndrome unmasking.

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Figure 1. Surface 12 lead EKG recordings after Ceftazidime administration. Limb leads show a QT interval of 520 msec.

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Figure 2. Surface 12 lead EKG recordings after Ceftazidime administration. Precordial leads showing a QT interval of 520 msec.

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Figure 3. Surface 12 lead EKG recordings after stopping Ceftazidime. Limb and precordial leads show a QT interval of 400 msec.

INVESTIGATIONS:

-coronarographywas normal.
-thyroid function was normal
-cardiac enzymes were normal without elevation of troponine in spite of electrical defibrillation.
-ejection fraction was normal, without conduction troubles.
-Electrophysiological study was performed.

After injection of low dose adrenaline -0.02 mcg/kg/min the heart rate increased with decrease of the QT interval 360 msec.

After injection of high dose adrenalne – 0.2 mcg/kg/min the heart rate further increased with further decrease of the QT interval: 340 msec.

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Figure 4. Adrenaline test. QT interval at the begining of infusion = 470 msec.

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Figure 5. Adrenaline test After 5 minutes of 0.025 mcg/kg/min same QT interval 470 msec.

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Figure 6: Adrenaline test After 5 minutes of 0.05 mcg/kg/min, shortening of the QT interval 425 msec.

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Figure 7: Adrenaline test After 5 minutes of 0.1 mcg/kg/min, shortening of the QT interval 413 msec.

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Figure 8. Adrenaline test. After 5 mintues of 0.2 mcg/kg/min, shortening of the QT interval 394 msec.

TREATMENT :

The patient received an implantable defibrillator.

LEARNING POINTS:

- Epinephrine test shows increase in the QT interval wih low dose infusion, which is patognomonic for LQT1 syndrome.
- Epinephrine unmask concealed long QT syndrome
- Ventriculo-atrial conduction is sometimes very resistant to antiarrhythmic drugs.
- When pacemaker syndrome occurs, implantation of a double chamber pacemaker can solve the problem.

REFERENCES:

- Bos JM, Ackerman MJ, Epinephrine test for sudden cardiac death-is it too early ? Nat Rev Cardiol.2012;9:675-676.
- Richter S, Muessigbrodt A, Salmas J, Doering M, Wetzel M, Arya A, Hindricks G, Brugada P, Israel CW. Ventriculoatrial conduction and related pacemaker-mediated arrhythmias in patients implanted for atrioventricular block: An old problem revisited. International Journal of Cardiology 2013;168:3300-8.
- Westveer DC, Stewart JR, Goodfleish R, Gordon S, Timmis GC. Prevalence and significance of ventriculoatrial conduction. Pacing Clin Electrophysiol 1984;7:784-9.
- Wiper A, Jenkins NP, Roberts DH. Pacemaker syndrome-a forgotten diagnosis ? British Journal of Cardiology 2008;15 :46-7.
- Hariman RJ, Pasquariello JL, Gomes JA, Holtzman R, El-Sherif N. Autonomic depdendence of ventriculoatrial conduction. Am J Cardiol 1985;56:285-91.
- R Nietzsce, M Guenoun, D Lamaison et al. Endless-loop tachycardias: description and first clinical results of new fully automatic protection algorithm. PACE 1990;13:1711-8.

• Hochschule: Universitatea de Medicină și Farmacie Iuliu Hațieganu Cluj-Napoca (Medizinische und Pharmazeutische Universität Iuliu Hațieganu) (Cardiology Rehabilitation)
• Note: 10
• Autor: Dr. Gabi Cismaru (Autor:in)
• Erscheinungsjahr: 2017
• Seiten: 9
• Katalognummer: V359255
• ISBN (eBook): 9783668488076
• ISBN (Buch): 9783668488083
• Sprache: Englisch
• Schlagworte: adrenaline, Long QT syndrome, Ceftazidime