A report on Artificial cardiac pacemaker

St. Jude Medical single-lead pacemaker with ruler (released in 2005 )

An ECG in a person with an atrial pacemaker. Note the circle around one of the sharp electrical spikes in the position where one would expect the P wave.

An ECG of a person with a dual chamber pacemaker

ECG rhythm strip of a threshold determination in a patient with a temporary (epicardial) ventricular pacemaker. The epicardial pacemaker leads were placed after the patient collapsed during aortic valve surgery. In the first half of the tracing, pacemaker stimuli at 60 beats per minute result in a wide QRS complex with a right bundle branch block pattern. Progressively weaker pacing stimuli are administered, which results in asystole in the second half of the tracing. At the end of the tracing, distortion results from muscle contractions due to a (short) hypoxic seizure. Because decreased pacemaker stimuli do not result in a ventricular escape rhythm, the patient can be said to be pacemaker-dependent and needs a definitive pacemaker.

Right atrial and right ventricular leads as visualized under x-ray during a pacemaker implant procedure. The atrial lead is the curved one making a U shape in the upper left part of the figure.

Three leads can be seen in this example of a cardiac resynchronization device: a right atrial lead (solid black arrow), a right ventricular lead (dashed black arrow), and a coronary sinus lead (red arrow). The coronary sinus lead wraps around the outside of the left ventricle, enabling pacing of the left ventricle. Note that the right ventricular lead in this case has two thickened aspects that represent conduction coils and that the generator is larger than typical pacemaker generators, demonstrating that this device is both a pacemaker and a cardioverter-defibrillator, capable of delivering electrical shocks for dangerously fast abnormal ventricular rhythms.

Posteroanterior and lateral chest radiographs of a pacemaker with normally located leads in the right atrium (white arrow) and right ventricle (black arrowhead), respectively.

Two types of remote monitoring devices used by pacemaker patients

In 1958, Arne Larsson (1915–2001) became the first to receive an implantable pacemaker. He had 26 devices during his life and campaigned for other patients needing pacemakers.

Illustration of implanted cardiac pacemaker showing locations of cardiac pacemaker leads

The first lithium-iodide cell-powered pacemaker. Invented by Anthony Adducci and Art Schwalm. Cardiac Pacemakers Inc. 1972

Medical device that generates electrical impulses delivered by electrodes to the chambers of the heart either the upper atria, or lower ventricles to cause the targeted chambers to contract and pump blood.

- Artificial cardiac pacemaker

53 related topics with Alpha

Electrocardiography

10 links

Process of producing an electrocardiogram , a recording of the heart's electrical activity.

A 12-lead ECG of a 26-year-old male with an incomplete right bundle branch block (RBBB)

Proper placement of the limb electrodes. The limb electrodes can be far down on the limbs or close to the hips/shoulders as long as they are placed symmetrically.

The limb leads and augmented limb leads (Wilson's central terminal is used as the negative pole for the latter in this representation)

Diagram showing the contiguous leads in the same color in the standard 12-lead layout

QRS is upright in a lead when its axis is aligned with that lead's vector

Schematic representation of a normal ECG

Measuring time and voltage with ECG graph paper

Formation of limb waveforms during a pulse

Use of real time monitoring of the heart in an intensive care unit in a German hospital (2015), the monitoring screen above the patient displaying an electrocardiogram and various values of parameters of the heart like heart rate and blood pressure

Among other things, an ECG can be used to measure the rate and rhythm of heartbeats, the size and position of the heart chambers, the presence of any damage to the heart's muscle cells or conduction system, the effects of heart drugs, and the function of implanted pacemakers.

Ventricular fibrillation (VF) showing disorganized electrical activity producing a spiked tracing on an electrocardiogram (ECG)

Arrhythmia

8 links

Too fast or too slow.

Broad classification of arrhythmias according to region of heart required to sustain the rhythm

Normal sinus rhythm, with solid black arrows pointing to normal P waves representative of normal sinus node function, followed by a pause in sinus node activity (resulting in a transient loss of heartbeats). Note that the P wave that disrupts the pause (indicated by the dashed arrow) does not look like the previous (normal) P waves – this last P wave is arising from a different part of the atrium, representing an escape rhythm.

Treatments may include medications, medical procedures such as inserting a pacemaker, and surgery.

Heart

8 links

Muscular organ in most animals.

Computer-generated animation of a beating human heart

The human heart is in the middle of the thorax, with its apex pointing to the left.

Heart being dissected showing right and left ventricles, from above

Frontal section showing papillary muscles attached to the tricuspid valve on the right and to the mitral valve on the left via chordae tendineae.

Layers of the heart wall, including visceral and parietal pericardium

The swirling pattern of myocardium helps the heart pump effectively

Arterial supply to the heart (red), with other areas labelled (blue).

Development of the human heart during the first eight weeks (top) and the formation of the heart chambers (bottom). In this figure, the blue and red colors represent blood inflow and outflow (not venous and arterial blood). Initially, all venous blood flows from the tail/atria to the ventricles/head, a very different pattern from that of an adult.

The cardiac cycle as correlated to the ECG

The x-axis reflects time with a recording of the heart sounds. The y-axis represents pressure.

Transmission of a cardiac action potential through the heart's conduction system

The prepotential is due to a slow influx of sodium ions until the threshold is reached followed by a rapid depolarization and repolarization. The prepotential accounts for the membrane reaching threshold and initiates the spontaneous depolarization and contraction of the cell; there is no resting potential.

3D echocardiogram showing the mitral valve (right), tricuspid and mitral valves (top left) and aortic valve (top right).
The closure of the heart valves causes the heart sounds.

Heart and its blood vessels, by Leonardo da Vinci, 15th century

Elize Ryd making a heart sign at a concert in 2018

The tube-like heart (green) of the mosquito Anopheles gambiae extends horizontally across the body, interlinked with the diamond-shaped wing muscles (also green) and surrounded by pericardial cells (red). Blue depicts cell nuclei.

Basic arthropod body structure – heart shown in red

The human heart viewed from the front and from behind

Heart illustration with circulatory system

Animated Heart 3d Model Rendered in Computer

Cardiac devices in the form of pacemakers or implantable defibrillators may also be required to treat arrhythmias.

View of defibrillator electrode position and placement

Defibrillation

6 links

Treatment for life-threatening cardiac arrhythmias, specifically ventricular fibrillation and non-perfusing ventricular tachycardia (V-Tach).

Self-adhesive electrodes of a defibrillator

Anterior-apex placement of electrodes for defibrillation

Defibrillator with pad positions shown: the model is biphasic and either pad can be placed in each position

A circuit diagram showing the simplest (non-electronically controlled) defibrillator design, depending on the inductor (damping), producing a Lown, Edmark or Gurvich Waveform

Implantable cardioverter-defibrillators, also known as automatic internal cardiac defibrillator (AICD), are implants similar to pacemakers (and many can also perform the pacemaking function).

Implantable cardioverter-defibrillator

4 links

Illustration of Implantable Cardioverter Defibrillator (ICD)

A single chamber ICD with its right ventricular lead connected into the header; note, starting from the end of the lead, the tip and adjacent first ring, used to sense the cardiac electrical activity and stimulate the right ventricle, the coil and the two rings for atrial sensing.

A normal chest X-ray after placement of an ICD, showing the ICD generator in the upper left chest and the ICD lead in the right ventricle of the heart. Note the 2 opaque coils along the ICD lead.

Lead II electrocardiogram (known as "rhythm strip") showing torsades de pointes being shocked by an implantable cardioverter-defibrillator back to the patient's baseline cardiac rhythm.

An implantable cardioverter-defibrillator (ICD) or automated implantable cardioverter defibrillator (AICD) is a device implantable inside the body, able to perform defibrillation, and depending on the type, cardioversion and pacing of the heart.

Heart failure

4 links

Set of manifestations caused by the failure of the heart's function as a pump supporting the blood flow through the body.

Signs and symptoms of severe heart failure

Kerley B lines in acute cardiac decompensation. The short, horizontal lines can be found everywhere in the right lung.

Model of a normal heart (left); and a weakened heart, with over-stretched muscle and dilation of left ventricle (right); both during diastole

Chest radiograph of a lung with distinct Kerley B lines, as well as an enlarged heart (as shown by an increased cardiothoracic ratio, cephalization of pulmonary veins, and minor pleural effusion as seen for example in the right horizontal fissure. Yet, no obvious lung edema is seen. Overall, this indicates intermediate severity (stage II) heart failure.

Siderophages (one indicated by white arrow) and pulmonary congestion, indicating left congestive heart failure

Ultrasound showing severe systolic heart failure

Congestive heart failure with small bilateral effusions

Sometimes, depending on the cause, an implanted device such as a pacemaker or an implantable cardiac defibrillator may be recommended.

Cardiac pacemaker

4 links

Initiated by electrical impulses known as action potentials.

Schematic representation of the sinoatrial node and the atrioventricular bundle of His. The location of the SA node is shown in blue. The bundle, represented in red, originates near the orifice of the coronary sinus, undergoes slight enlargement to form the AV node. The AV node tapers down into the bundle of HIS, which passes into the ventricular septum and divides into two bundle branches, the left and right bundles. The ultimate distribution cannot be completely shown in this diagram.

In humans, and sometimes in other animals, a mechanical device called an artificial pacemaker (or simply "pacemaker") may be used after damage to the body's intrinsic conduction system to produce these impulses synthetically.

Heart block

3 links

Disorder in the heart's rhythm due to a fault in the natural pacemaker.

Sinus rhythm with acute inferior infarction complicated by Type I AV block manifest in the form of 5:4 Wenckebach periods; R-P/P-R reciprocity.

Sinus tachycardia with complete AV block and resulting junctional escape

Despite the severe-sounding name, heart block may cause no symptoms at all in some cases, or occasional missed heartbeats in other cases (which can cause light-headedness, syncope (fainting), and palpitations), or may require the implantation of an artificial pacemaker, depending upon exactly where in the heart conduction is being impaired and how significantly it is affected.

$Orthopedic implants to repair fractures to the radius and ulna. Note the visible break in the ulna. (right forearm)$

Implant (medicine)

2 links

Medical device manufactured to replace a missing biological structure, support a damaged biological structure, or enhance an existing biological structure.

$Orthopedic implants to repair fractures to the radius and ulna. Note the visible break in the ulna. (right forearm)$

A coronary stent — in this case a drug-eluting stent — is another common item implanted in humans.

AMS 800 and ZSI 375 artificial urinary sphincters

Complications can arise from implant failure. Internal rupturing of a breast implant can lead to bacterial infection, for example.

In some cases implants contain electronics, e.g. artificial pacemaker and cochlear implants.

Bradycardia

5 links

Slow resting heart rate, commonly under 60 beats per minute (BPM) as determined by an electrocardiogram.

Illustration comparing the ECGs of a healthy person (top) and a person with bradycardia (bottom): The points on the heart where the ECG signals are measured are also shown.

Treatment often consists of the administration of atropine and cardiac pacing.