…malfunction are associated with the electronics in the pulse generator or dislodgement or fracture of the leads. External causes are less common and include electrolyte…

…delivered by the pulse generator can be calculated as follows: I = V/R Given that voltage (V) is constant and battery depletion must be…

…consist of an implantable pulse generator (IPG) , which contains the electronics, a battery , and one or two leads . The pulse generator generates the electric current…

…interrogation and reprogramming are warranted in higher risk circumstances, particularly for pacing dependent patients, patients with CRT, and ICD recipients undergoing procedures likely to generate…

…image are drawn with varying shades of one color (usually gray). This is possible because the vibrations in the piezoelectric crystals, and thus the electric…

…a piezoelectric crystal, it starts to vibrate and these vibrations generate sound waves with frequencies between 1.5 and 8 MHz (i.e ultrasound). Thus…

…pressure control. Mechanism of action Nitroprusside provides nitric oxide (NO) that induces vasodilatation of both arterioles and veins via generation of cyclic GMP, which then…

…approximately 20–50%. Their greater analytical sensitivity improves diagnostic accuracy and negative predictive value in patients with suspected acute coronary syndrome (ACS). Cardiac troponin is…

…response. The ECG in ectopic atrial rhythm and atrial tachycardia A regular rhythm with P waves that differ in contour from sinus P waves. If…

…mass), second (time), ampere (electric current) and Kelvin (temperature). This system is recommended globally. Amplitude Amplitude describes the strength of the sound waves, which corresponds…

…Efficient CPR generates approximately 25% of normal cardiac output, which postpones or mitigates cerebral injuries. No flow time and low flow time are critical parameters…

…arterioles and veins) via generation of cyclic GMP, which then activates calcium sensitive potassium channels in the cell membrane. Nitroglycerin is similar in action and…

…time dependent inward currents. This process creates early afterdepolarisations (EADs) that generate premature ventricular contractions (PVCs) and increases transmural dispersion of repolarisation, thereby facilitating reentry…

…early hours following infarction may be associated with hemodynamic compromise. More broadly, bradyarrhythmic arrest and asystole represent severe manifestations of impulse generation or conduction failure…

…inconclusive. The principal diagnostic strength of CCTA is its ability to exclude significant anatomical CAD with high sensitivity and a high negative predictive value, particularly…

…IVUS IVUS generates images by transmitting ultrasound from an intracoronary catheter and recording echoes reflected from the vessel wall. Contemporary systems use frequencies ranging from…

…PR interval and PR segment ECG interpretation starts with assessment of the P wave and PR interval. The P wave is generated by depolarization (activation…

…V2. lead V5 only notes vectors heading towards the exploring electrode (albeit with somewhat varying angles) and therefore displays a positive P wave throughout. Figure…

…in patients with a clinically unstable acute coronary syndrome, but the examination does not reliably establish or exclude the diagnosis. The ECG and serial assessment…

…testing may generate false positive results and unnecessary downstream procedures. In patients with a high probability, testing may add little diagnostic value and invasive coronary…

…Furthermore, AF induces a systemic hypercoagulable state, characterized by elevated biomarkers such as D dimer, von Willebrand factor, and increased thrombin generation. The clinical consequence…

…induce an inflammatory state similar to the Systemic Inflammatory Response Syndrome (SIRS). Body temperatures surpassing 40°C (104°F) are potentially hazardous and may precipitate cardiac arrest…

…mechanism. Sequential activation implies that the atria are activated first and they fill the ventricles with adequate volumes of blood before ventricular contraction commences. To…

…the conduction system are much too small to be detected by skin electrodes; the ECG presents the electrical activity of the atrial and ventricular myocardium…

…with regards to the patient, loading conditions. If repeated echocardiograms yield pronounced variations in ejection fraction, then it is likely that variations in preload and…

…a rapid atrial rate (e.g. during a supraventricular tachycardia) and stimulates the ventricles with the same rate. This occurs if ventricular stimulation is set…

…V6: placed on level with V4 and V5, in the mid axillary line. V4R: placed on the right medioclavicular line between rib 5 and 6…

…must overcome to eject blood into the aorta. Afterload affects myocardial muscle fibers during systole and diastole. Afterload is a function of the following three…

…the electrical potentials generated by the sinoatrial node are much too small to be detected on the surface ECG. Intracardiac electrodes – with the placement of…

…the sinoatrial node. They may also induce conduction defects (e.g. AV block). Increased intracranial pressure (manifests with sinus bradycardia and hypertension). Hypothyroidism . Hypothermia . Hyperkalemia …

…and repolarization generate electrical currents. It was also explained that the electrical currents are conducted all the way to the skin, because the tissues and…

…on observational data ( e.g compression rate and depth). With current strategies, compressions and ventilations can generate a cardiac output equivalent to 15 25% of…

…and whether there is a concomitant bundle branch block. Escape rhythms with narrow QRS complexes indicate that the block and the ectopic focus (which generates…

…to the high density of myocardium. It follows that myocardium generates reflections with high amplitude and low Doppler shift. To analyze reflections from the myocardium…

…Nonetheless, prompt interventions can reverse cardiac arrest and survivors of traumatic cardiac arrest often exhibit favorable neurological outcomes ( Rawshani et al ). Traumatic cardiac arrests typically…

…required and this takes about 40 milliseconds (ms) to generate. As illustrated previously (Axial and lateral resolution of the ultrasound image) line density diminishes with…

…flow generated CPAP with a PEEP valve. Masks in several sizes. An oronasal mask is first choice in the acute setting ; nasal masks and total…

…hydroxide ions are generated at the negative pole of the battery and produce a liquefactive necrosis that can reach the septal cartilage within a few…

…with a full stomach. Preparation and equipment A laryngeal mask of the correct size plus one size above and one below. Second generation masks with…

…due to sinus pause or post VPC pause) results in augmentation of early afterdpolarization amplitude (typically seen with large T wave amplitude), and QT prolongation…

…and left ventricular function. The HCM Risk SCD score aims to identify individuals with a high risk of SCD and determine whether an implantable cardioverter…

…foreign body. First generation DES, particularly sirolimus and paclitaxel eluting devices, were associated with increased late and very late stent thrombosis compared with BMS. Modern…

…restenosis compared with BMS, and newer generation DES have improved outcomes further. Nevertheless, clinically important ISR remains possible after DES implantation. Clinical Presentation and Symptoms…

…overcome by the ventricles. The left ventricle must overcome the pressure in the aorta and systemic circulation (normally 120 mmHg in adults). The right ventricle…

…Study Figure 7 carefully, as it illustrates how the P wave and QRS complex are generated by the electrical vectors. Note that the first vector…

…due to sinus pause or post VPC pause) results in augmentation of early afterdpolarization amplitude (typically seen with large T wave amplitude), and QT prolongation…

…type of stenosis. The patients with low flow (stroke volume index <35 ml/m²) and low gradient (<40 mmHg) displayed the worst prognosis. Adapted from…

…structures ( i.e structures with high echogenicity). For each reflection, a portion of the sound waves return to the transducer and produce a copy of…

…ECG as increased amplitudes of the QRS complexes. The explanation is straightforward: myocardial muscle mass is increased and therefore it generates greater electrical potentials. However…

…<0,12 seconds) indicate the ventricles are depolarized via the His Purkinje system and thus the impulse originates in the atria (i.e the arrhythmia…

…away from the transducer will generate reflections with lower frequency. Doppler shift The Doppler effect is utilized to calculate velocity and direction of moving objects…

…which may be due to dysfunction in the conduction system. The J point and the ST segment The ST segment corresponds to the plateau phase…

…by elevated natriuretic peptide levels and/or objective evidence of pulmonary or systemic congestion [3] . Within this spectrum, Heart Failure with Reduced Ejection Fraction (HFrEF…

…younger the patient presenting with hypertrophy, the more likely a genetic etiology. The genetic mechanisms underlying hypertrophic cardiomyopathy are complicated and some gene variants may…

…overcome by the ventricles. The left ventricle must overcome the pressure in the aorta and systemic circulation (normally 120 mmHg in adults). The right ventricle…

…NSTEMI is confirmed by a typical rise and/or fall of high sensitivity cardiac troponin (hs cTn), with at least one value above the 99th…

…discharged near the atrioventricular node, the atria will be depolarized in the opposite direction and thus generate a negative (retrograde) P wave (Figure 2). Thus…

…sample volume is depicted with two lines perpendicular to the Doppler line (Figure 2). Figure 2. Location of sample volume (SV) and the resulting spectral…

…from randomized trials and observational studies examining the efficacy of ICD (implantable cardioverter defibrillator). An ICD is programmed to detect VF/VT and defibrillate within…

…ventricles is slow because the impulse initially spreads outside of the His Purkinje system. The slow initial depolarization generates a delta wave on the ECG…