NURS 222 Exam #1 Study Guide: Dysrhythmias

Dysrhythmias

• Dysrhythmias, also known as arrhythmias, are abnormal heart rhythms that impair cardiac efficiency in pumping oxygenated blood.
• Normal sinus rhythm (NSR) originates from the SA node with a resting heart rate of 60-100 bpm and a regular rhythm.
• Key characteristics of NSR:
  • P waves: upright, consistent in size and shape, precede each QRS complex.
  • PR interval: 0.12 to 0.20 seconds.
  • QRS complex: lasts 0.04–0.44 seconds.
  • ST segment: should be on the baseline.
  • QT interval: varies but generally up to 0.44 seconds.
  • T waves: usually positive and less than 5 mm in height.

Sinus Tachycardia

• Characterized by heart rates exceeding 100 bpm, typically not exceeding 180 bpm.
• Regular rhythm with visible P waves before each QRS complex; P waves may merge with T waves at high rates.
• PR interval is normal (0.12-0.20 seconds), and QRS complex remains under 0.12 seconds.
• Symptoms include:
  • Often asymptomatic; possible hypovolemia, dehydration, decreased urinary output, and blood pressure.
  • Dry skin/mucous membranes, anginal pain, and palpitations.
• Nursing interventions include vital signs monitoring and assessing for dysrhythmias.

Heart Failure Indicators

• Left ventricular failure leads to decreased cardiac output, which can cause:
  • Dry/hack cough mistaken for asthma or COPD; may produce large quantities of pink frothy sputum in acute decompensated heart failure.
  • Pulmonary crackles indicate fluid accumulation; may not clear with coughing.
  • Low oxygen saturation and potential presence of S3 or gallop sounds.
• Right-sided heart failure symptoms include:
  • JVD and peripheral edema, especially in feet and ankles, worsening with prolonged sitting or standing.
  • Hepatomegaly and ascites, along with GI distress and weight gain due to fluid retention.
• Key nursing activities: monitoring fluid status, daily weights, adherence to low sodium diets, and anxiety management.

Mitral Valve Prolapse

• Occurs when mitral valve leaflets enlarge and prolapse into the left atrium during systole, which allows regurgitation of blood.
• Commonly asymptomatic but can manifest as fatigue, chest pain, SOB, dizziness, syncope, and palpitations.
• May result in a mid-systolic click and late systolic murmur.
• Nursing interventions include dietary restrictions (avoid stimulants), smoking cessation, and infection risk minimization.

Chronic Obstructive Pulmonary Disease (COPD)

• Symptoms include dyspnea, productive cough, wheezing, clubbing of fingers, and a barrel-shaped chest.
• Pathophysiology involves lower airway disorders affecting airflow and gas exchange, mainly emphysema and bronchitis.
  • Emphysema: Overdistended alveoli, difficulty exhaling, chronic hypercapnia, known as "pink puffers."
  • Bronchitis: Hypersecretion of mucus, difficulty inhaling, inflammation resulting in cyanosis, referred to as "blue bloaters."
• Cor pulmonale, a complication of severe COPD, may result in right ventricular hypertrophy and heart failure, presenting with symptoms like ascites and JVD.

Chest Tube Management

• Closed drainage systems are standard, with nursing responsibilities including monitoring for effective drainage and assessing the patient's respiratory status.
• Bubbling in the water-seal indicates air drainage; excessive bubbling suggests leaks while cessation could indicate blockage.
• Tidaling indicates normal respiratory movement.
• Nursing care includes:
  • Regularly assessing lung sounds and breathing effectiveness.
  • Inspecting the insertion site for infection or subcutaneous emphysema.
  • Encouraging deep breathing and coughing with the use of incentive spirometry.

Human Immunodeficiency Virus (HIV)

• HIV leads to the progressive depletion of CD4 T cells vital for immune defense against infections.
• Understood as a retrovirus, it contains RNA and uses reverse transcriptase to convert RNA into DNA in host cells.
• It transforms CD4 cells into virus-producing factories, ultimately disabling them.
• Important distinction: all individuals with AIDS are HIV positive, but not all who have HIV develop AIDS.

Prepare for your NURS 222 Exam #1 with this comprehensive study guide focusing on Chapter 28: Dysrhythmias. Understand the abnormal rhythms of the heart's electrical system and how disturbances affect oxygen delivery. Emphasize the Normal Sinus Rhythm and key concepts crucial for your nursing exam.