Ventricular arrhythmias: Pathology review
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Ventricular arrhythmias: Pathology review
Pathology
Vascular disorders
Arterial disease
Angina pectoris
Stable angina
Unstable angina
Myocardial infarction
Prinzmetal angina
Coronary steal syndrome
Peripheral artery disease
Subclavian steal syndrome
Aneurysms
Aortic dissection
Vasculitis
Behcet's disease
Kawasaki disease
Hypertension
Hypertensive emergency
Renal artery stenosis
Coarctation of the aorta
Cushing syndrome
Conn syndrome
Pheochromocytoma
Polycystic kidney disease
Hypotension
Orthostatic hypotension
Abetalipoproteinemia
Familial hypercholesterolemia
Hypertriglyceridemia
Hyperlipidemia
Chronic venous insufficiency
Thrombophlebitis
Deep vein thrombosis
Lymphedema
Lymphangioma
Shock
Vascular tumors
Human herpesvirus 8 (Kaposi sarcoma)
Angiosarcomas
Congenital heart defects
Truncus arteriosus
Transposition of the great vessels
Total anomalous pulmonary venous return
Tetralogy of Fallot
Hypoplastic left heart syndrome
Patent ductus arteriosus
Ventricular septal defect
Coarctation of the aorta
Atrial septal defect
Cardiac arrhythmias
Atrial flutter
Atrial fibrillation
Premature atrial contraction
Atrioventricular nodal reentrant tachycardia (AVNRT)
Wolff-Parkinson-White syndrome
Ventricular tachycardia
Brugada syndrome
Premature ventricular contraction
Long QT syndrome and Torsade de pointes
Ventricular fibrillation
Atrioventricular block
Bundle branch block
Pulseless electrical activity
Valvular disorders
Tricuspid valve disease
Pulmonary valve disease
Mitral valve disease
Aortic valve disease
Cardiomyopathies
Dilated cardiomyopathy
Restrictive cardiomyopathy
Hypertrophic cardiomyopathy
Heart failure
Heart failure
Cor pulmonale
Cardiac infections
Endocarditis
Myocarditis
Rheumatic heart disease
Pericardial disorders
Pericarditis and pericardial effusion
Cardiac tamponade
Dressler syndrome
Cardiac tumors
Cardiac tumors
Cardiovascular system pathology review
Acyanotic congenital heart defects: Pathology review
Cyanotic congenital heart defects: Pathology review
Atherosclerosis and arteriosclerosis: Pathology review
Coronary artery disease: Pathology review
Peripheral artery disease: Pathology review
Valvular heart disease: Pathology review
Cardiomyopathies: Pathology review
Heart failure: Pathology review
Supraventricular arrhythmias: Pathology review
Ventricular arrhythmias: Pathology review
Heart blocks: Pathology review
Aortic dissections and aneurysms: Pathology review
Pericardial disease: Pathology review
Endocarditis: Pathology review
Hypertension: Pathology review
Shock: Pathology review
Vasculitis: Pathology review
Cardiac and vascular tumors: Pathology review
Dyslipidemias: Pathology review
Assessments
Ventricular arrhythmias: Pathology review
USMLE® Step 1 questions
0 / 6 complete
Questions
USMLE® Step 1 style questions USMLE
of complete
Image reproduced from Wikimedia Commons
The patient is shocked multiple times and dies despite resuscitation efforts. Post-mortem analysis is most likely to demonstrate which of the following as the etiology of this patient’s clinical presentation?
Transcript
Content Reviewers
Antonia Syrnioti, MD
Clint is a 19 year old male that’s brought to the emergency department for acute chest pain. Upon examination, you notice that his heart rate is really fast, about 170 beats per minute. He has a history of depression, and is currently being treated with TCAs. He is otherwise healthy. A few minutes after arriving, Clint loses consciousness. His ECG shows this.
All right, so based on his presentation and ECG, Clint has some form of arrhythmia. The best way to approach arrhythmias is to one: know what a normal ECG looks like, and two: have a good classification system to narrow down the diagnosis. To help identify an irregular rhythm, you can look at the morphology of the waveform and make sure that there is a P wave before every QRS complex, and a QRS complex after every P wave.
Now let’s take a look at the heart rate. The resting heart beats at a rate between 60 to 100 times per minute, and each of those beats starts off with depolarization of the sinoatrial node, and so we call it a normal sinus rhythm. It's also important to know that there is typically a delay in the conduction at the AV node and the Bundle of His, which gives some time for ventricular filling before the ventricle contracts. On the ECG, this is represented by the PR interval, which should be less than 5 small boxes, or 200 milliseconds.
Now, any disturbance in the rate, rhythm, site of origin, or conduction of the cardiac electrical activity is called an arrhythmia. Arrhythmias could be completely asymptomatic, and be picked up incidentally on an ECG. Arrhythmias can also present with palpitations, which is a sensation of your heart beating too hard or fast, fluttering, or skipping a beat. Additionally, they may alter cardiac output, causing individuals to present with signs of hypotension and decreased brain perfusion, like dizziness, altered mental status, or syncope.
Summary
An arrhythmia is any disturbance in the rate, rhythm, site of origin, or conduction of the cardiac electrical impulse. Ventricular arrhythmias are those that originate within the ventricles and have a wide QRS complex on ECG. These two types of ventricular arrhythmias are ventricular tachycardia and ventricular fibrillation.
Ventricular tachycardia can be monomorphic meaning that all the QRS complexes look the same, or polymorphic meaning the QRS complexes are different in each beat. A specific and very dangerous type of polymorphic ventricular tachycardia is Torsades de Pointes, which presents a twisting pattern of QRS complexes. This can rapidly progress to ventricular fibrillation, in which the whole PQRST ECG pattern breaks down completely, leaving just some random undulating waves. This is the most common cause of sudden cardiac death.
Sources
- "Robbins Basic Pathology" Elsevier (2017)
- "Monomorphic ventricular tachycardia as the primary presentation of an anterior STEMI" Clinical Case Reports (2019)
- "Drug induced QT prolongation and torsades de pointes" Heart (2003)
- "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
- "Pathophysiology of Heart Disease" Wolters Kluwer Health (2015)
- "Brugada syndrome: A general cardiologist's perspective" European Journal of Internal Medicine (2017)
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