Download Use of dothiepin for management of Wenkebach

Use of dothiepin for management of Wenkebachtype second degree heart block
Jeenal Patel, Jayne Hui
Box Hill Hospital, Eastern Health
Background
Dothiepin is a tricyclic
antidepressant (TCA) which inhibits
the reuptake of noradrenaline and
serotonin and blocks cholinergic and
alpha-adrenergic receptors1.
Infrequent adverse effects (0.1-1%)
of TCAs include snius tachycardia,
arrhythmias and QT prolongation1,2.
Objective
To report a successful case of
dothiepin use in treating PR
prolongation due to Wenkebachtype second degree heart block.
Day 6
-Medical review
-Ventricular pauses
likely due to
increased vagal tone
in setting of sepsis.
-Wenckebach pattern
seen on ECG
-Isoprenaline ceased
-Atropine PRN
commenced
Day 0
-Admission with
urosepsis
-JJ Stent inserted
-Ceftriaxone 1g
initiated
Day 3
- Ventricular pauses seen on
ECG
- Transfer to cardiology ward
- IV isoprenaline commenced
- Ceftriaxone ceased
Figure 1: Timeline of Clinical Presentation and Management
Figure 3: Relevant Biochemistry during
Patient Admission
Clinical Features
An 80 year old caucasian female
was admitted with E.coli urosepsis,
successfully treated with JJ stent
insertion and ceftriaxone 1g IV daily.
Ventricular pauses were seen on
electrocardiogram (ECG) day 3 post
procedure and the patient was
transferred to the cardiology unit.
Discussion
Wenkebach-type second degree
heart block describes non-conducted
P waves that occur due to
prolongation of the PR interval,
because of fatigue of AV node cells.3
As there is minimal progression to
third degree heart block, only
symptomatic patients are treated.
Atropine is the treatment standard.3
Case Progress and Outcomes
Initially, cardiology planned for
permanent pacemaker (PPM)
insertion when sepsis was resolved.
On day 6, ECG highlighted
Wenckebach pattern of PR
prolongation prior to ventricular
pauses, suggesting type-1 second
degree heart block.3 Isoprenaline
was ceased and atropine as
required commenced.
There is paucity of evidence to
support the use of dothiepin in this
setting, as a known side effect of
TCAs is PR prolongation.4 However,
past literature does suggest tricyclic
antidepressants such as imipramine
may demonstrate anti-arrythmic
effect.4 This is the first case report of
such dothiepin use to our
knowledge. The mechanism of
action for this effect has not been
established.
Permanent pacemakers are not
required for Wenkebachtype second degree heart block.
Dothiepin 25mg daily was initiated
on Day 9 and increased over three
days to 50mg, resulting in less
ventricular pauses on telemetry. The
patient was discharged on dothiepin
50mg daily.
Day 9
- Dothiepin 25mg
daily initiated by
cardiology team
Day 11
-Dothiepin
dose
increased to
50mg daily
- Patient
discharged
Day 1
Day 3
Day 6
Day 10
Hb
-
116
118
128
Na+
-
140
140
139
K+
-
4.0
4.3
4.6
Mg2+
-
1.0
-
0.89
Cr
-
56
62
60
eGFR
-
85
82
83
BP
(mmHg)
130/66
141/76
-
130/65
Heart
Rate
(BPM)
108
58
-
80
Conclusion
This case demonstrates the
successful initial use of dothiepin in
the management of ventricular
pauses in a patient with
Wenckebach-type second degree
heart block. Further research is vital
in ascertaining this mechanism of
action and duration of treatment.
Figure 2: Past Medical History and
Medications Taken Prior to Admission
Past Medical
History
Medications on
admission
Hypertension
amlodipine 10mg/
valsartan 160mg
1 po daily
Glaucoma
brinzolamide 1%
eye drops;
travoprost 0.004%
eye drops
Hypercholesterolaemia
Untreated
Osteoarthritis
Untreated
For further information, please contact Jeenal
Patel at [email protected]
References
1. Australian Medicines Handbook. Adelaide; Australian
Medicines Handbook Pty Ltd; 2016
2. Dothiepin. In: Adverse Effects [database on the Internet].
Ann Arbor (MI): Truven Health Analytics; 2016 [cited 20
Sept 2016]. Available from:www.micromedexsolutions.com
3. AV Block: 2nd degree, Mobitz I. Life in the Fast
Lane;2016 [cited 20 Sept 2016]. Available from:
http://lifeinthefastlane.com/ecg-library/basics/wenckebach/
4. Glassman A. Cardiovascular Effects of Therapeutic
Doses of Tricyclic Antidepressants. Arch Gen Psychiatry;
1981, 38:815-820.