Cardiac Rhythms 2

First Degree Heart Block

cardiac conduction system is delayed in transmitting an electrical signal through the right atrium to the AV node.

• conduction through the AV node is abnormally slow or prolonged, this results in a PR interval > 0.20 seconds​​​​​​.

First Degree Heart Block Cause

• increasing of age

• history of cardiac disease (such as MI or coronary artery disease)

• electrolyte imbalances (including hypokalemia and hypomagnesemia)

• certain antiarrhythmic medications

  • Sodium channel blockers (Lidocaine)

  • Beta blockers (Metoprolol)

  • Calcium channel blockers (Diltiazem)

  • Potassium channel blockers (Amiodarone)

  • Cardiac glycosides (Digoxin)

  • Magnesium

• endocarditis, rheumatic fever, and COVID-19

• rheumatoid arthritis, lupus, and sarcoidosis

• Athletes

First Degree Heart Block Sx

Typically no manifestations

• dizziness with changes in position or shortness of breath with activity

First Degree Heart Block Labs

serum electrolytes or drug toxicology testing

• ECG : prolonged PR interval that will be > 0.20 seconds

First Degree Heart Block Education

• avoid smoking and alcohol and to eat a healthy, low-cholesterol diet.

• Exercise routines will need to be monitored to ensure that the client avoids excessive fatigue.

• Information should be provided on potential adverse effects of prescribed medications.

First Degree Heart Block Tx

atropine or isoproterenol. Pacemaker insertion may be necessary to treat the underlying cause of the heart block.

Afib Patho

SA node is not firing appropriately. The electrical stimuli are being sent from multiple areas in the atria and are transmitting electrical impulses that are rapid, chaotic, and irregular.

• These irregular impulses do not allow the atria to effectively contract and send blood into the ventricles.

• Cardiac output is decreased + BLOOD CLOT FORMATION

Afib Risk Factors

• Diabetes

• Hyperthyroidism

• OSA

• Hx smoking or excessive alcohol

• Sedentary Lifestyle

• recovering from cardiac surgery

Afib Comorbidities

high blood pressure, heart failure, diabetes mellitus, overweight and obesity, chronic obstructive pulmonary disorder, thyroid disease, kidney disease, and stroke.

• Untreated A-fib increases the incidence of stroke and heart failure

Afib Sx

• Irregular pulse

• hypotension

• heart palpitations and increased heart rate

• chest discomfort

• shortness of breath (either at rest or with activity) or exertional fatigue

• anxiety

• dizziness or lightheadedness, and possible syncopal episodes.

• Weight gain and increased urination may also be reported.​​​​​​​

• Pulse deficit

Afib Labs

• Thyroid panel (decreased TSH, increased T4…hyper)

• CBC

• Creatinine

• Glucose

• INR

• P waves are replaced by indiscernible (unidentifiable) atrial activity between QRS complexes. The ventricular rate can be within normal range (60 to 100/min) or increased range (100 to 200/min).

Afib Education

• Educate on anticoagulant adherence and not “catch up” on any missed doses

• precautions to prevent unexpected bleeding, such as using a soft-bristled toothbrush, shaving with safety razors or an electric razor, and avoiding contact sports or high-risk activities that may result in injury.

• refrain from highly intensive physical activities

• importance of maintaining a healthy weight, limiting the intake of alcohol, and the need to avoid smoking.

• the need to avoid stimulants, including caffeine, over-the-counter decongestants, illicit stimulant drugs, and herbal supplement

• adequately controlling sleep apnea, blood glucose levels, blood pressure, and weight gain.

• Warfarin and vitamin K

Afib Tx

• synchronized electrical cardioversion.

• antiarrhythmic medications

  • Beta blockers, calcium channel blockers, amiodarone, and digoxin

• anticoagulation therapy for stroke prevention

  • warfarin or DOACs (xa-)

Atrial Flutter Patho

occurs when the atria are beating in a regular rhythm and increased rate.

• atrial rates can range from 240 to 400 bpm.

• This is caused by multiple, rapid electrical impulses being sent from the atria too quickly for the AV node to process before the transmission to the ventricles.

Atrial Flutter Risk Factors

• Recent cardiac surgery

• Recent MI

• beta blockers, calcium channel blockers, amiodarone, or digoxin

• diabetes

• hyperthyroidism

• obstructive sleep apnea

• obesity

• alcohol use and smoking

• history of cardiomyopathy or pericarditis

Atrial Flutter Sx

• hypotension

• lightheadedness or dizziness

• palpitations or chest discomfort

• shortness of breath (with activity or at rest)

• fatigue

• syncopal episodes.

Atrial Flutter Labs

• electrolytes and liver, kidney, and thyroid functions.

• ECG ; normal heart rhythm. P waves are replaced by multiple sawtooth or flutter waves between QRS complexes. The ventricular rate is typically normal, between 60 to 100/min, and the atrial rate is increased, between 240 to 340/min.

Atrial Flutter Tx

• anticoagulants (to prevent blood clot formation)

• antiarrhythmics (to control rhythm)

• Rate control medications (beta blockers, calcium channel blockers, amiodarone, digoxin),

• Procedures to convert the rhythm back to NSR (synchronized electrical cardioversion, cardiac ablation

Supraventricular Tachycardia (SVT) Patho

occur when electrical impulses are originating from above the AV node and these impulses cause excessive excitability of the atrial tissue, resulting in an increased heart rate.

SVT Cause

• increased stress levels

• smoking or intake of alcohol, caffeine, and other stimulating substances.

• history of heart disease or failure, Wolff-Parkinson-White syndrome, pregnancy, or chronic lung disease.

SVT Comorbidities

• CAD

• HTN

• Diabetes

• Afib

• HF

• Cardiomyopathy

• Hyperthyroid

• Renal disease

• Cardiac rhythm abnormalities, such as sinus tachycardia, atrial fibrillation, and atrial flutter, can lead to the development of SVT or PSVT.

SVT Sx

• hypotension

• syncope

• shortness of breath

• abrupt onset of heart palpitations or chest discomfort

• dizziness or lightheadedness

SVT Labs

• blood tests will include electrolytes, CBC, and thyroid function

• ECG: regular rhythm, increased heart rate of 100 to 220 bpm, and a characteristic narrow QRS complex measuring < 0.12 seconds and undiscernible P wave

SVT Education

• Provide information on vagal maneuvers that will be used in an attempt to terminate SVT or PSVT

• Valsalva maneuver, the client will be asked to hold their breath for 15 seconds while bearing down as if having a bowel movement.

SVT Tx

• Vagal maneuvers such as forceful coughing, gagging, carotid massage via the provider or Valsalva maneuver

• intravenous adenosine may be administered.

• Continuous heart monitoring

• intravenous medications, including diltiazem, esmolol, or metoprolol, can be used in an attempt to slow down the increased heart rate.