Tachycardia
Arrhythmia
•Arrhythmia is an uneven heartbeat .It is a conduction disorder. Aberrant rhythms can be initiated anywhere in the conduction system, from SA node down to level of an individual myocyte.
•Abnormalities in myocardial conduction can be sustained or paroxysmal.
•They can be manifest as fast heart rate, tachyarrhythmia, also called tachycardia. And as slow heart rate, bradyarrhythmia, also called bradycardia, or asystole.
Normal sinus rhythm
Normal sinus rhythm refers to generation of impulse from the SA node at a rate of 60-100 beats/min in an adult, rates below 60 beats/min are referred to as bradycardia and rates above 100 beats/min are referred to as tachycardia.
•Rhythm: Regular
•Rate: 60 – 100 beats/min
•P waves: upright and uniform
•PRI: 0.12 – 0.20 sec; constant
•QRS: Narrow(< 0.10 sec); sometimes wide
Tachycardia:-
•Tachycardia is defined as a heart rhythm with a ventricular rate of 100 beats/minute or greater.
•
•Tachycardia are characterized on the basis of originate above the ventricle are referred to as supraventricular tachycardia (SVTs).
•Those that originate from the ventricle or purkinje fibres are characterized as ventricular tachycardia.
Epidemiology:-
•Incidence rate of Atrial flutter was 578 per 100,000 person years. Mean age of individuals at flutter diagnosis was range 53–92 years, and 30% were women.
(Source: Rahman et. al., 2016 Atrial flutter: clinical risk factors and adverse outcomes in the Framingham Heart Study. Heart Rhythm, 13(1), 233-24
•The prevalence of Atrial Fbrillation increased 3-fold over the last 50 years. The Global Burden of Disease project estimated a worldwide prevalence of AF around 46.3 million individuals in 2016
(Source: Kornej J. et. al., 2020, Epidemiology of Atrial Fibrillation in the 21st Century, Novel Methods and New Insights. Circulation Research, 127(1), 4-20
•The prevalence of ventricular tachycardia is approximately 54,000 per 100,000 in men and 55,000 per 100,000 in women with hypertension , valvular heart disease.
(Source: https://www.wikidoc.org/index.php/Ventricular_tachycardia_epidemiology_and_demographics)
•
•The incidence of SVT is approximately 35 cases per 100,000 patients with a prevalence of 2.25 cases per 1,000 in the general population.
(Source: https://cisresearch.com/psvt
•Atrioventricular nodal reentrant tachycardia (AVNRT) is considered a sporadic disease occurring in ≈ 22.5 cases per 10 000 in the general population.
(Source: https://www.ahajournals.org/doi/full/10.1161/CIRCEP.116.004680)
•Multifocal atrial tachycardia is a relatively uncommon arrhythmia seen in 0.05% to 0.32% of electrocardiograms in general hospital admissions.
(Source: https://www.ncbi.nlm.nih.gov/books/NBK459152/#article-25345)
•The incidence of cardiac tamponade based on a giant sample size of about 216 million emergency admissions was about 115,638(0.05%)
(Source: https://www.wikidoc.org/index.php/Cardiac_tamponade_epidemiology_and_d
emographics)
•The prevalence of WPW syndrome is approximately 100-300 per 100000 individuals worldwide.
(Source: https://www.wikidoc.org/index.php/Wolff-Parkinson-White_syndrome_epidemiology_and_demographics)
Risk Factors
- •Anemia
- •Diabetes
- •Cardiovascular disease
- •Heavy alcohol use
- •Heavy caffeine use
- •Use of stimulant drugs
- •Smoking
Etiology
•Normal response to
•Exercise , pain, stress, fever, strong emotions
•Certain cardiac conditions
•Heart failure
•Medications
•Epinephrine and atropine
•Substances
•Caffeine, nicotine and cocaine
•Other conditions
•Anemia, respiratory distress, pulmonary embolism, sepsis and hyperthyroidism
Clinical Manifestation:-
•Shortness of breath
•Lightheadedness
•Rapid pulse rate
•Heart palpitation
•Chest pain
Classification:-
. Sinus Tachycardia
•Rhythm: regular
•Rate: more than 100bpm.
•P wave: normal( up right, rounded)
•PR Interval: normal
•QRS Complex: normal duration
•ST Segment: isoelectric
•T Wave: normal ( symmetric, rounded)
•Conduction: normal electrical path way
B. Atrial fibrillation
•Rate: Atrial: >350 bpm; Ventricular: variable
•Rhythm: Irregular
•P Waves: No true P waves; chaotic atrial activity
•PR Interval: None
•QRS: Normal ( 0.06 – 0.10 sec)
C. Atrial Flutter
•P wave = Sawtooth appearance
•PR Interval = Unable to measured
•QRS Complex= Narrow
•Rate = Between 200 – 300 beats/min
•Rhythm = Regular rhythm
•Loss of the isoelectric baseline.
D. AV Node Reentrant Tachycardia
•Rate = Between 150 – 250 beats/min.
•Regular R-R interval.
•Narrow QRS complex.
E. Atrial Tachycardia
•Rate = More than 140 – 250 beats/min
•QRS complex =Narrow
•P Wave = Abnormal P before each QRS (difficult to see)
•PR Interval =Difficult to distinguish
•Rhythm = Irregular
F. Multifocal Atrial Tachycardia
•Heart rate = 100 – 150 beats/min
•Rhythm = Irregular rhythm
•P Wave = At least 3 distinct P wave morphologies in the same lead
•QRS Complex =Normal
•PR Interval = Variable
G. Cardiac Tamponade
•Low QRS voltage
•Electrical alternates
•Sinus tachycardia
H. Junctional Tachycardia
•Heart Rate = More than 100 beats/min
•Rhythm = Regular
•QRS Complex = Narrow complex
•P waves = inverted in II, III or absent P waves
•PR interval = Short(<120 ms)
Wide QRS Complex:-
A. Ventricular tachycardia
•Heart rate = More than 100 beats/min
•Rhythm = Irregular
•P Wave = Absent
•PR Interval = Absent
•QRS complexes = Wide(> 120ms)
B. Supraventricular Tachycardia
•Rhythm = Regular
•Rate =150 – 200 bpm
•P Wave = Difficult to determine-may be hidden.
•PR interval = Normal or Shortened.
•QRS complex = Normal
C. Wolf-Parkinson-White Syndrome
•Short PR interval (<120 ms).
•Wide QRS complex longer
than 120 ms.
D. Pacemaker-Tracked Tachycardia
•Left bundle branch block pattern on ECG.
These are some form of Diagnosis:-
The management of Tachycardia depends on the rhythm types,
the ACLS protocal:-
Synchronized Cardioversion:
Initial recommended doses:
•Narrow regular: 50 – 100J
•Narrow Irregular: 120 – 200J biphasic or 200J monophasic
•Wide regular: 100J
•Wide irregular: defibrillation dose (not synchronized)
Adenosine IV Dose:
•First dose: 6 mg rapid IV push; follow with NS flush
•Second dose: 12 mg if required.
Antiarrhythmic infusions for Stable Wide-QRS Tachycardia
Procainamide IV dose:
20-50 mg/min until arrhythmia suppressed, hypotension ensues, ORS duration increases >50% or maximum dose 17 mg/kg given. Maintenance infusion: 1-4 mg/min. Avoid if prolonged QT or CHF.
Antiarrhythmic infusions for Stable Wide-QRS Tachycardia
Amiodarone IV dose:
First dose: 150 mg over minutes. Repeat as needed if VT recurs. Follow by maintenance infusion of 1 mg/min for first 6 hours.
Antiarrhythmic infusions for Stable Wide-QRS Tachycardia
Sotalol IV dose:
100 mg (1.5 mg/kg) over 5 minutes.
Avoid if prolonged QT.
Antiarrhythmic infusions for Stable Wide-QRS Tachycardia
Sotalol IV dose:
100 mg (1.5 mg/kg) over 5 minutes.
Avoid if prolonged QT.
Nursing Management:-
Assessment
•Complete past and present history taking of patient and patients family members.
•Perform physical examination.
•Monitor electrocardiogram.
•Monitor vital sign.
• Any past and present medications history.
Nursing Diagnosis:-
•Knowledge deficit as evidence by patient verbalization and asking questions.
•Anxiety as evidence by facial expressions.
•Ineffective breathing pattern related to increased oxygen requirements as evidence by shortness of breath.
•Risk for decrease cardiac output related to altered electrical conduction.
Interventions that could be done according to the above diagnosis are:-
•Palpate pulses( radial, carotid, femoral, dorsalis pedis), noting rate, regularity
•Auscultate heart sounds, noting rate, rhythm, presence of extra heartbeats
• Monitor vital signs
•Determine type of tachycardia
•Provide quite and calm environment
•Demonstrate and encourage use of stress management
•Investigate reports of chest pain, documenting location, duration, intensity
•Monitor laboratory studies
•Administer medications as indicated
•Assess patient and level of knowledge and ability and desire to learn.
•Encourage identification and reduction of individual risk factors: smoking and alcohol consumption, obesity.
•Identify adverse effects and complication of tachycardia.
•Instruct and document teaching regarding medications.
•Encourage development of regular exercise routine, avoiding overexertion.
•Review individual needs and restrictions: potassium, caffeine.
