Alternatively, the simple process of normal aging can adversely affect the hearts ability to maintain normal rhythms. Normal cardiac rhythm occurs when spontaneous electrical impulses generated in the sinoatrial sa node are transmitted via the specialized conducting pathways to working myocardium. Arrhythmiaboth atrial and ventricularis a common comorbidity with hypertension ht. These result in the postcardiac arrest syndrome, which affects many systems in the body, but in particular the brain, heart, and kidneys. Cardiac arrhythmias john a kastor,university of maryland, baltimore. Almost two decades after the lancet s groundbreaking arrhythmia octet in 1993, cardiac electrophysiology has developed as a subspecialty so successfully that specialist cardiology units are now likely to have almost as many electricians as plumbers, according to andrew grace, who orchestrated the current series one recurring theme of the series is the successful application of. Request pdf on feb, 2019, dhinakaran s and others published arrhythmias. Basic cardiac rhythms identification and response utmc. Arrhythmia types in the next video well talk about arrhythmia medication, so.
The term arrhythmia refers to any change from the normal sequence of electrical impulses. Automaticity can further be subdivided into 1 automaticity caused by. Occasionally, polyuria results from release of atrial natriuretic peptide during prolonged. Request pdf pathophysiology of cardiac arrhythmias. Vf is the most commonly identified arrhythmia in cardiac arrest patients. Certain inherited congenital heart defects can cause abnormalities within the developing electrical system that can appear even before birth. Pathophysiology, incidence, management, and consequences. The cardiac diseases that lead to the genesis of the arrhythmia resulting in cardiac collapse and sudden death are varied, and the association with sudden death in some cases is poorly understood. Reentry loops occur in branched, dysfunctionalfibrotic myocardium w. Once the diagnosis of tcmp has been made, many authors advocate a proactive treatment approach. Cardiac arrhythmias mechanisms, pathophysiology, and.
Describe the normal cardiac anatomy and physiology and normal. Volume 106 number 4, part 2 arrhythmia pathophysiology 809 tion in the cardiac syncytium in which they are measured 6 spach et al. Other increased risks are of embolisation and stroke, heart failure and sudden cardiac death. Cardiac arrhythmias mechanisms, pathophysiology, and treatment. The exact strategy employed is dependent on the causative arrhythmia, as detailed below, where either a rate or rhythm control strategy may. Atrial pressure increased in heart failure due to increased blood volume and venous tone treated with salt restriction and diuretics afterload. Arrhythmia etiology arrhythmia pathophysiology the. Arrhythmia pathophysiology and treatment pharmacotherapy 1. Furthermore, understanding the physiology of arrhythmogenesis. Pharm, 3rd year, 6th semester netaji subhas chandra bose institute of pharmacy tatla, roypara, chakdaha, distnadia, pin 741222 affiliated to maulana abul kalam azad university of technology bf142, sector 1, saltlake city. Pathophysiologic mechanisms of cardiac arrhythmias. The underlying mechanism for the origins of vf is poorly understood, but prolonged monomorphic vt is a known risk factor, contributed by ischaemia, free radical production, and intracellular.
Ventricular fibrillation is one type of arrhythmia that can be deadly. Cardiac or cardiovascular syncope is caused by various heart conditions, such as bradycardia, tachycardia or certain types of hypotension. Arrhythmogenesis and types of arrhythmias as a pumping organ with an intrinsic electrical system, the. Arrhythmias may cause sudden death, syncope, heart failure, dizziness, palpitations or no symptoms at all. Overview of arrhythmias cardiovascular disorders msd. Once the diagnosis of tcmp has been made, many authors. This causes pumping chambers in your heart the ventricles to quiver uselessly instead of pumping blood. Antiarrhythmic drugs to maintain sinus rhythm in patients with atrial fibrillation. Defination cardiac arrhythmia is a condition in which the heart beats with an irregular or abnormal rhythm. Without an effective heartbeat, blood pressure plummets. The aim of the present chapter was to provide a concise overview of available data regarding epidemiology and pathophysiology of ventricular arrhythmias in several noncardiac diseases, to mention the main methods used to assess arrhythmia risk, as well. For clarity and simplicity of text, we will refer to the group 1 pah and group 4 cteph patients collectively as pahcteph, unless otherwise noted. Pathophysiology and causes of cardiac arrest oxford medicine.
The electrical impulses may happen too fast, too slowly, or erratically causing the heart to beat too fast, too slowly, or erratically. An abnormality of the cardiac rhythm is called a cardiac arrhythmia. Acls guidelines are also utilized in assisting the students in arrhythmia identi. The genesis of cardiac arrhythmias is generally categorized into disorders of impulse formation, disorders of impulse conduction, or combinations of both. People suspected of having cardiac syncope but who dont have serious medical conditions may. Isbn 9789535112211, pdf isbn 9789535171911, published 20140212. Pathophysiology of dr kamran afzal learning oje tives.
Arrhythmias occur in both normal and diseased hearts and have no medical significance in and of themselves, although they may endanger heart function when coupled with other cardiac. Clinical electrophysiology we have endeavored to relate known electrophysiologic mechanisms of arrhythmia development to clinically occurring arrhythmias, realizing that definitive conclusions can only be surmised at present. Pathophysiology of cardiac arrhythmias springerlink. Identify hemodynamic consequences of various rhythms 4. Cardiac dysrhythmias pathophysiology and therapeutic. Arrhythmia pathophysiology and treatment pharmacotherapy.
A large number of biochemical pathways are activated as a result of the cpa. Describe the electrical conduction system of the heart 3. The expectation is that they will be able to identify the arrhythmia type on lead ii and learn the standard advanced cardiac life support acls treatment guidelines for this form of arrhythmia 7,12. The cardiac action potential results from the sequential opening and. Arrhythmias result from abnormalities of impulse initiation or impulse conduction or a combination of both. Several schemes have been used to classify the mechanisms of cardiac arrhythmias. Ventricular fibrillation vf is a lifethreatening cardiac arrhythmia in which the coordinated contraction of the ventricular myocardium is replaced by highfrequency, disorganized excitation, resulting in the effective failure of the heart to pump blood. The american heart association has information about atrial fibrillation, quivering heart, bradycardia, slow heart rate, premature contraction, tachycardia, fast beat, ventricular fibrillation, fluttering heart, rhythm disorders, treatment of arrhythmia, symptoms of arrhythmia, diagnosis of arrhythmia, monitoring the heart, and much more. Heart failure mat maurer, md associate professor of clinical medicine objectives at the conclusion of this seminar, learners will be able to.
Ventricular arrhythmias and sudden cardiac death bja. Disturbances in cardiac rhythm are a result of abnormalities in impulse initiation, or conduction, or both. Basic mechanisms of cardiac arrhythmias intechopen. Sprague1 the raabe college of pharmacy, ohio northern university, ada oh 45810 prologue.
Pathophysiology of cardiac arrhythmias automaticity reentry loops an impulse travels continuously around a circular re entrant path in the myocardium, continuously depolarizing that cardiac region. Seminar on cardiac arrhythmia and its treatment submitted by souvik pal roll no. This depends critically on the preceding electrical activation. If an arrhythmia results in a heartbeat that is too fast, too slow or too weak to supply the bodys needs, this manifests as a lower blood pressure and may cause lightheadedness or dizziness, or syncope fainting. Classification, pathophysiology, and mechanisms of af. Ventricular fibrillation vf is a lifethreatening, chaotic rhythm, with marked variability in cycle length and morphology up to 300 beats min. Underlying mechanisms are many and various, including left ventricular hypertrophy lvh, myocardial ischemia, impaired left ventricular function and left atrial enlargement. Vascular resistance increased due to reflex sympathetic outflow and reninangiotensin system though elevated afterload. It occurs when the heart beats with rapid, erratic electrical impulses. Define and employ the terms preload, afterload, contractilty, remodeling, diastolic dysfunction, compliance, stiffness and capacitance. Identification of the patient at risk for sudden death and identification of the factors that precipitate the fatal arrhythmia continue to represent. Abnormal impulse initiation results from either automaticity or triggered activity. The teaching of the pathophysiology and pharmacological treatment of cardiac arrhythmias can be a challenging task.
548 414 543 1298 92 454 234 746 938 1021 239 871 535 54 945 511 313 844 915 1356 78 1360 656 1379 762 1454 1136 951 348 984