“Sick Sinus Syndrome” plus 2 more nursing article(s): NursingCrib.com Updates

Sick Sinus Syndrome
Congenital Heart Disorders – Disorders with Decreased Pulmonary Blood Flow
Hepatic Encephalopathy

Posted: 01 Dec 2010 04:54 PM PST

Sick sinus syndrome, also called sinus node dysfunction, is a group of abnormal heart rhythms (arrhythmias) presumably caused by a malfunction of the sinus node, the heart’s primary pacemaker. It is likely to affect adults older than age 70. Many people with sick sinus syndrome eventually need a pacemaker to keep the heart in a regular rhythm.

Types of sick sinus syndrome and their causes include:

Sinoatrial block where electrical signals move too slowly through the sinus node, causing an abnormally slow heart rate
Sinus arrest where the sinus node activity pauses
Tachycardia-bradycardia syndrome where the heart rate alternates between abnormally fast and slow rhythms, often with a long pause (asystole) between heartbeats.

Pathophysiology:

Scar tissue from a previous heart surgery may cause Sick sinus syndrome, particularly in children. It may also be set off by medications, such as calcium channel blockers or beta blockers that are used to treat high blood pressure, heart disease or other conditions. However, in most cases, the sinus node doesn’t work properly because of age-related wear and tear to the heart muscle.

Signs and symptoms:

Slower than normal pulse (bradycardia)
Fatigue
Dizziness or lightheadedness
Fainting or near-fainting
Shortness of breath
Chest pains
Trouble sleeping
Confusion or difficulty remembering things
Palpitations

Diagnostic Evaluation:

Standard electrocardiogram (ECG)
Holter monitor ECG a portable device is carried in a pocket or shoulder strap, which automatically records the heart’s activity for an entire 24-hour period, which provides the doctor with an extended look at the heart rhythms
Event recorder ECG -portable electrocardiogram device that can be carried in a pocket or worn on a belt or shoulder strap for home monitoring of heart's activity. But, unlike a Holter monitor, it doesn’t record continuously. Whenever there is an occurrence of symptoms, you push a button, and a brief ECG strip recording is made.

Medical Management:

Treatment for sick sinus syndrome focuses on eliminating or reducing unpleasant symptoms. Regular checkups to monitor the condition are very important. For people who are bothered by symptoms, the treatment of choice is usually an implanted electronic pacemaker. But if you have a pacemaker and your heart rate is still too fast, your doctor may prescribe anti-arrhythmia medications to prevent fast rhythms. If you have atrial fibrillation or other abnormal heart rhythms that increase your risk of stroke, you may need a blood-thinning medicine, such as warfarin (Coumadin).

Nursing Management:

Encourage regular check-up to a cardiologist.
Encourage also proper compliance to medications as well as in the diet regimen.
Avoid activities that are strenuous
Always be up to date about the status of the evaluations as well as the therapy needed.
Listen to concerns of the patient and the family with the several lifestyle changes.

Photo Credits: www.lookfordiagnosis.com

Congenital Heart Disorders – Disorders with Decreased Pulmonary Blood Flow

Posted: 01 Dec 2010 04:49 PM PST

Disorders with Decreased Pulmonary Blood Flow

Obstruction to pulmonary blood flow decreases the flow of the blood in the pulmonary circulation. Because of the obstruction present, pressure of the right side of the heart increases. Increase pressure of the right side of the heart can open the foramen ovale at birth (Atrial Septal Defect) or ventricular septal defect (VSD) can be present. This results to the invasion of deoxygenated blood in the systemic circulation. Disorders under this classification of congenital heart disease include tetralogy of fallot or tricuspid atresia.

Tricuspid Atresia

Tricuspid valve is located in between the right atrium and ventricle. This flap of tissue opens to pressure to allow blood to be drained in the right ventricle to the pulmonary circulation. In tricuspid atresia (atresia means absence of opening), as the name implies, the tricuspid valve is absent or completely closed. This prevents the blood to enter the right ventricle.

Due to the increasing pressure of the right atrium, the foramen ovale opens at birth resulting to an astrial septal defect. The blood crosses the foramen and goes directly into the atrium bypassing the step of oxygenation. Thus, blood is pumped into the systemic circulation completely deoxygenated. Blood can be shunted back to the lungs for oxygenation if the ductus arteriosus is patent. Open foramen ovale and patent ductus arteriosus can meet a child's oxygenation needs.

When these structures are closed the infant will developed the following clinical manifestations:

Cyanosis
Tachycardia
Dyspnea

Tetralogy Of Fallot

Tetralogy of fallot presents with four cardiac anomalies namely:

Ventricular Septal Defect (VSD) – usually large. Opening between the right and left ventricles.
Pulmonary stenosis – narrowing of the pulmonary valve or pulmonary artery distal to it.
Dextroposition (overriding) of the aorta – aorta overrides both ventricles
Hypertrophy of the right ventricle

Clinical Manifestations

Cyanosis (bluish skin)
Polycythemia (increase in the number of red blood cells) – the body attempts to provide the body with oxygen by increasing the RBC levels. Elevated RBC concentration in the blood results to increased viscosity and clots in the blood vessels may occur. Complications of polycythemia include thrombophlebitis, embolism or cerebrovascular accident.
Severe dyspnea
Growth restriction
Clubbing of the fingers
Squatting or knee-chest position when resting (physiologic relief from an overstressed heart by trapping blood in the lower extremities)
Syncope (fainting)
Tet spells (hypoxic episodes) – follows after prolonged crying or exertion

Images from health.allrefer.com, nlm.nih.gov, healthline.com

Hepatic Encephalopathy

Posted: 01 Dec 2010 04:44 PM PST

Hepatic encephalopathy is the occurrence of confusion, altered level of consciousness and coma as a result of liver failure. It occurs when the liver is no longer able to remove toxic substances in the blood. It is also known as portosystemic encephalopathy. In the advanced stages it is called hepatic coma or coma hepaticum.

It is said to be triggered by dehydration, eating too much protein, electrolyte abnormalities (especially a decrease in potassium), bleeding from the intestines, stomach, or esophagus, infections, kidney problems, low oxygen levels in the body and use of medications that suppress the central nervous system (such as barbiturates or benzodiazepine tranquilizers).

Diagnostic Evaluation:

Requires the presence of impaired liver function
Blood tests (such as high ammonia levels) may assist in the diagnosis.

Signs and Symptoms:

Early symptoms:

forgetfulness
mild confusion
irritability

Intermediate stages:

jerking movement of the limbs is observed (asterixis, “liver flap” due to its flapping character)
jaundice (yellow discoloration of the skin and the whites of the eyes)
ascites (fluid accumulation in the abdominal cavity)
peripheral edema (swelling of the legs due to fluid build-up in the skin)

More severe encephalopathy:

an inverted sleep-wake pattern (sleeping by day, being awake at night)
marked irritability
tremor
difficulties with coordination
trouble writing.

Severe form of encephalopathy:

lethargy to somnolence
eventually coma

Treatment:

Hepatic encephalopathy is reversible with treatment. This relies on suppressing the production of the toxic substances in the intestine and so lactulose was widely used.

The antibiotics neomycin and metronidazole were previously used as a treatment for hepatic encephalopathy. However, it is known that neomycin and similar aminoglycoside antibiotics may cause hearing loss and renal failure if used extensively. While Metronidazole, was also discarded because prolonged use could cause a peripheral neuropathy.

A safer and probably more effective antibiotic is rifaximin, a nonabsorbable antibiotic from the rifamycin class. This is thought to work in a similar way, but without the complications attached to neomycin and metronidazole. However, whenever acute liver failure occurs, it may indicate liver transplant.

Photo credits: www.lookfordiagnosis.com