Last reviewed: 25 Sep 2021
Last updated: 29 Jun 2021

Summary

Definition

History and exam

Key diagnostic factors

  • pulse rate <50 bpm
  • age >70 years
  • use of known causative medications
  • presence of known underlying cause
  • dizziness/lightheadedness
  • syncope
  • fatigue
  • exercise intolerance
  • shortness of breath
  • cannon a-waves in jugular venous pulse
  • jugular venous distension

Other diagnostic factors

  • increased intracranial pressure
  • abnormal heart sounds
  • abdominal or lower extremity edema
  • hypotension
  • mental status changes
  • pallor
  • extremities cool to touch
  • hypothermia
  • chest pain
  • rashes
  • thyroid goiter

Risk factors

  • use of known causative medications
  • age >70 years
  • recent myocardial infarction
  • surgery
  • percutaneous valve replacement procedures
  • hypothyroidism
  • electrolyte disorders
  • acidosis
  • infections
  • exposure to toxins
  • hypothermia
  • infiltrative diseases
  • sleep apnea
  • epilepsy

Diagnostic investigations

1st investigations to order

  • 12-lead ECG
  • Holter monitoring
  • event monitor/mobile cardiac telemetry
  • exercise testing
  • carotid sinus massage
  • echocardiogram
  • thyroid function tests
  • basic metabolic panel
  • arterial blood gas
  • cardiac biomarkers
  • serum digoxin level
  • serum creatinine

Investigations to consider

  • implantable-loop recorder
  • tilt-table testing
  • Lyme titers
  • electrophysiology testing
  • nocturnal pulse oximetry or overnight polysomnography

Treatment algorithm

Contributors

Authors

Brian Olshansky, MD, FAHA, FACC, FHRS, FESC
Brian Olshansky

Professor Emeritus

University of Iowa

Iowa City

Adjunct Professor

Des Moines University

Electrophysiologist

Mercy Hospital North Iowa

Mason City

Covenant Hospital

Waterloo

IA

Disclosures

BO is a national research study coordinator for Boehringer Ingelheim. He is a consultant and speaker for Lundbeck. He is a consultant for Amarin and was chair of the DSMB of REDUCE-IT He is a consultant for Sanofi Aventis and Respicardia.

Sandeep Saha, MD, MS, FACP, FACC

Cardiologist and Cardiac Electrophysiologist

Oregon Heart Center

Consultant, Cardiology and Cardiac Electrophysiology

Salem Health Hospitals and Clinics

Salem

OR

Disclosures

SS declares that he has no competing interests.

Rakesh Gopinathannair, MD, MA, FAHA, FACC, FHRS
Rakesh Gopinathannair

Director, Cardiac Electrophysiology Laboratories

Kansas City Heart Rhythm Institute and Research Foundation

EP Medical Director

Research Medical Center, HCA Midwest Health

Overland Park

KS

Clinical Professor of Medicine

University of Missouri-Columbia

Columbia

MO

Associate Professor of Medicine (adjunct)

University of Louisville

Louisville

KY

Disclosures

RG is a consultant for St. Jude Medical, Biotrionik, and Boston Scientific. He is on the speakers' bureau for Pfizer Inc. and Zoll Medical. He serves as a physician advisor for HealthTrust PG and AltaThera Pharma, and PaceMate. None of these activities are relevant to the content of this topic.

Acknowledgements

Professor Brian Olshansky, Dr. Sandeep Saha, and Professor Rakesh Gopinathannair would like to gratefully acknowledge Dr Giselle Statz for her contributions to this version of the topic. They would also like to acknowledge Dr Renee M. Sullivan, Dr Weiwei Li, Dr Alexander Mazur, and Dr Chirag M. Sandesara, previous contributors to this topic.

Disclosures

GS, RMS, WL, AM, and CMS declare that they have no competing interests.

Peer reviewers

Nora Goldschlager, MD

Professor of Clinical Medicine

University of California

Chief

Clinical Cardiology

San Francisco General Hospital

Director

Coronary Care Unit

ECG Laboratory and Pacemaker Clinic

San Francisco

CA

Disclosures

NG declares that she has no competing interests.

Paul Heidenreich, MD

Associate Professor of Medicine

Stanford University

Stanford

CA

Disclosures

PH declares that he has no competing interests.

Juan M. Sztajzel, MD

Cardiology Center and Medical Polyclinics

University Hospital Geneva

Geneva

Switzerland

Disclosures

JMS declares that he has no competing interests.

Use of this content is subject to our disclaimer