Sinus Tachycardia

Brief History and Physical:

A young female with a history of schizophrenia presents to the emergency department reporting hallucinations. She had been diagnosed with schizophrenia one year previously and was briefly admitted to a psychiatric hospital. She discontinued her anti-psychotic (risperidone) two months ago, and over the past week she reports increasingly prominent auditory and visual hallucinations.

She denies recent illness, vomiting/diarrhea, changes in urinary habits, new medications, alcohol or illicit substance use. She also denies chest pain, palpitations or shortness of breath.

Vital signs are notable for a heart rate of 148bpm and are otherwise normal (including core temperature). Detailed physical examination is normal except for a rapid, regular heart rate. Mental status examination demonstrated normal level of alertness and orientation, linear and cogent responses and occasional response to internal stimuli during which she appeared anxious.

Initial evaluation and management included a 12-lead ECG which showed sinus tachycardia. Multiple boluses of normal saline were initiated while awaiting laboratory workup.

ECG: Sinus Tachycardia

Presentation ECG demonstrates sinus tachycardia.

Update:

Laboratory studies were reviewed and unremarkable. Normal hemoglobin, normal chemistry panel, negative hCG, and negative toxicology screen. The patient remained persistently tachycardic with a heart rate ranging from 140-160bpm (again sinus tachycardia on 12-lead ECG). An atypical antipsychotic and anxiolytic were administered and additional studies were obtained. Serum TSH, troponin and D-dimer were normal and bedside ultrasound did not identify a pericardial effusion. The patient remained asymptomatic, reporting subjective improvement in anxiety and hallucinations. Psychiatry was consulted and the patient was placed in observation for monitoring of sinus tachycardia. Observation course was uneventful as the patient remained asymptomatic. Transthoracic echocardiography was normal. Psychiatry consultation recommended resumption of home anti-psychotic and outpatient follow-up. Tachycardia had improved but not resolved at the time of discharge (heart rate 109bpm) and the patient was instructed to follow-up with her primary care provider.


Algorithm for the Evaluation of Sinus Tachycardia

Algorithm for the Evaluation of Sinus Tachycardia

Any vital sign derangement is concerning and tachycardia may be associated with unanticipated death after discharge home1. The presence of tachycardia suggests one of several categories of hemodynamic, autonomic, or endocrine/metabolic derangement.

Demand for increased cardiac output

A perceived demand for increased cardiac output will prompt chronotropic (and inotropic) amplification before hypotension develops. Causative etiologies include: volume depletion (from hemorrhage, gastrointestinal or renal losses), distributive processes (such as infection), obstruction (pulmonary embolus, or pericardial effusion with impending tamponade), or tissue hypoxia (anemia or lung disease).

Autonomic nervous system

Autonomic nervous system disturbances induced by stimulant, sympathomimetic or anti-cholinergic use, or withdrawal of certain agents such as ethanol or beta-blockers may be at fault.

Endocrine and other causes

Hyperthyroidism and pheochromocytoma should be considered, and as diagnoses of exclusion: anxiety, pain, or inappropriate sinus tachycardia2.

Evaluation:
Core temperature
CBC
Troponin
D-dimer
Bedside cardiac ultrasound
Urine toxicology screen
Ethanol level
TSH/T4

Algorithm for the Evaluation of Narrow-Complex Tachycardia3,4,5,6

Algorithm for the Evaluation of Narrow-Complex Tachycardia

References:

  1. Sklar DP, Crandall CS, Loeliger E, Edmunds K, Paul I, Helitzer DL. Unanticipated Death After Discharge Home From the Emergency Department. Ann Emerg Med. 2007;49(6):735-745. doi:10.1016/j.annemergmed.2006.11.018.
  2. Olshansky B, Sullivan RM. Inappropriate sinus tachycardia. J Am Coll Cardiol. 2013;61(8):793-801. doi:10.1016/j.jacc.2012.07.074.
  3. Yusuf S, Camm AJ. Deciphering the sinus tachycardias. Clin Cardiol. 2005;28(6):267-276.
  4. Katritsis DG, Josephson ME. Differential diagnosis of regular, narrow-QRS tachycardias. Heart Rhythm. 2015;12(7):1667-1676. doi:10.1016/j.hrthm.2015.03.046.
  5. Bibas L, Levi M, Essebag V. Diagnosis and management of supraventricular tachycardias. CMAJ. 2016;188(17-18):E466-E473. doi:10.1503/cmaj.160079.
  6. Link MS. Clinical practice. Evaluation and initial treatment of supraventricular tachycardia. N Engl J Med. 2012;367(15):1438-1448. doi:10.1056/NEJMcp1111259.

Palpitations

Brief H&P

48F with a history of Grave disease (off medications for 4 months), presenting with palpitations. Noted gradual onset of palpitations while at rest, describing a pounding sensation lasting 3-4 hours and persistent (though improved) on presentation. Symptoms not associated with chest pain, shortness of breath, loss of consciousness, nor triggered by exertion. She reported a history of 8-10 episodes in the past for which she did not seek medical attention. Review of systems notable only for heat intolerance.

On physical examination, vital signs were notable for tachycardia (HR 138bpm). No alteration in mental status, murmur, tremor or hyperreflexia appreciated.

Labs

  • Hb: 14.7
  • Urine hCG: negative
  • TSH: <0.01
  • Total T3: 311ng/dL
  • Free T4: 2.64ng/dL

ECG

Palpitations - Sinus Tachycardia

Sinus Tachycardia

Impression/Plan

Palpitations due to sinus tachycardia from symptomatic hyperthyroidism secondary to medication non-adherence. Improved with propranolol, discharged with methimazole and PMD follow-up.

Differential Diagnosis of Palpitations1, 2

Differential Diagnosis of Palpitations

Evaluation of Palpitations

History and Physical

Subjective description of symptom quality
Rapid and regular beating suggests paroxysmal SVT or VT. Rapid and irregular beating suggests atrial fibrillation, atrial flutter, or variable conduction block.
Stop/start sensation: PAC or PVC
Rapid fluttering: Sustained supraventricular or ventricular tachycardia
Pounding in neck: Produced by canon A waves from AV dissociation (VT, complete heart block, SVT)
Onset and offset
Random, episodic, lasting instants: Suggests PAC or PVC
Gradual onset and offset: Sinus tachycardia
Abrupt onset and offset: SVT or VT
Syncope
Suggests hemodynamically significant arrhythmia, often VT
Examination
Identify evidence of structural, valvular heart disease

ECG1

ECG Finding Presumed etiology
Short PR, Delta waves WPW, AVRT
LAA, LVH Atrial fibrillation
PVC, BBB Idiopathic VT
Q-waves Prior MI, VT
QT-prolongation VT (polymorphic)
LVH, septal Q-waves HCM
Blocks  

Algorithm for the Evaluation of Palpitations3

Algorithm for the Evaluation of Palpitations

References

  1. Zimetbaum P, Josephson ME. Evaluation of patients with palpitations. N Engl J Med. 1998;338(19):1369-1373. doi:10.1056/NEJM199805073381907.
  2. Probst MA, Mower WR, Kanzaria HK, Hoffman JR, Buch EF, Sun BC. Analysis of emergency department visits for palpitations (from the National Hospital Ambulatory Medical Care Survey). The American Journal of Cardiology. 2014;113(10):1685-1690. doi:10.1016/j.amjcard.2014.02.020.
  3. Abbott AV. Diagnostic approach to palpitations. Am Fam Physician. 2005;71(4):743-750.

Syncope

ID:

A 50 year-old male with a reported two-year history of infrequent spells, presenting with two spells in the past two days.

HPI:

The patient’s spells began two years ago, he recounts that he was watching television when he lost consciousness and a friend noted he started shaking; he does not recall the event, and awoke in the hospital. The next spell occurred one year later, though the patient is unable to recall much about this episode. The patient remained spell-free until yesterday when he was on a bus, lost consciousness and awoke in a hospital. He notes that he had bit his tongue and lost control of his bladder. He was discharged hours later with a prescription for an AED which he was unable to fill. This morning, the patient had another spell while in the bathroom. His roommate heard him fall, found him on the ground, and noted that his mouth was moving but did not see any other movements.

The patient’s episodes are all associated with loss of consciousness and are followed by 5-10 minutes of disorientation after which he recovers fully. The episodes are sometimes preceded by a feeling of “euphoria”, though this feeling sometimes occurs without subsequent LOC.

The patient denies any associated palpitations, dizziness/LH, chest pain or muscle pain.  He has not had any recent fevers/chills, dysuria, cough, headache, changes in vision, numbness/tingling, weakness, difficulty speaking or swallowing or weight loss. He also denies any history of head trauma.

Physical Examination:

  • VS: Stable and WNL
  • General: Well-appearing, pleasant, and in NAD.
  • HEENT: NC/AT. MMM. Small lesion on tongue.
  • Lungs: CTAB.
  • CV: RRR with occasional ectopic beats, no M/R/G.
  • Abdomen: S/NT/ND. Bowel sounds present.
  • Neurological exam: AAOx4, CN II-XII intact, motor/sensation/reflexes/coordination/gait WNL

Imaging/Studies:

  • EKG: Occasional PAC/PVC
  • CT Brain: Unremarkable except for mild age-related cerebral atrophy

Assessment & Plan:

50 year-old male with a history of HTN and a reported two-year history of infrequent spells presenting with two spells in the past two days. The description of the patient’s episodes could be consistent with seizures. Aspects supporting this notion include loss of consciousness and period of confusion following each episode. One of the recent episodes was also associated with tongue-biting and loss of bladder control. Additionally, some episodes are associated with a sensation of euphoria rising from the abdomen to the head which could be indicative of an aura. Characteristics that suggest other causes include the absence of noted convulsions and non-stereotyped nature of each episode which could be due to the patient’s poor recollection of these events and absence of reliable witnesses. In the case of true seizures, the possible etiologies in this patient include a mass, metabolic abnormalities, substance use, or concomitant infection exacerbating an existing propensity for seizure activity. Other, non-seizure causes warranting evaluation include cardiogenic syncope particularly given the evidence of ectopic beats on examination and electrocardiogram.

Differential Diagnosis of Syncope

First, is it syncope? History is very important for distinguishing syncope from other causes (seizure, dizziness, vertigo, presyncope). Ask about precipitating events, prodromal symptoms, post-ictal confusion. Common causes of syncope and their associated symptoms are detailed in the figure below.

References:

  1. Kapoor, W. N. (2000). Syncope. The New England journal of medicine, 343(25), 1856–1862. doi:10.1056/NEJM200012213432507