DETECTION OF PREMATURE VENTRICLE CONTRACTION

A) Electro-Physiography of Cardio Pulmonary System:

Heart can be viewed as a 2-stage pump actually organized in shunt but in a series of flowing blood passing through the pumps. The blood is pumped to the body with the help of the right half of the heart. The circulating pathway for blood flowing over the lungs is called pulmonary flow and is also the network that deliveries the body’s cells with oxygen and nutrients is called Systematic flow.

The difference between the arteries and veins is small in pulmonary circulation as is the resistance to flow, then the right heart is assumed as pressure pump. The plates, the arteries and the veins are not stiff but flexible. With the use of their own muscular action and their receptor they control the blood flow in our body.

On the right side, blood reaches the heart, through 2 veins, SUPERIOR VENA CAVA AND INFERIOR VENA CAVA. The incoming blood fills the right atrium storage space. The coronary sinus comprises the blood which has passed into the coronary loop in the heart itself.

Through Right ventricles and tricuspid the blood is pushed once the right atrium is filled and it pumps the blood into the pulmonary flow system as the ventricular pressure reaches the atrial pressure of the tricuspid valve clods and the pressure in the ventricle causes the pulmonary valve to open.

The interchange takes place within the alveoli of the lungs. Oxygen recharges the red blood cells and gives up CO2. The PULMONARY ARTERY splits several times in smaller arteries that are very small cross-section arterioles. Such arteries provide blood to capillaries of alveolus in which the exchange of O2 and CO2 occurs. The same construction is on the other side of the lungs mass capillary feed into tiny veins and veneoles

From ‘PULMONARY VEIN’ the blood arrives ‘LEFT ATRIUM’ and from there it is driven into ‘LEFT VENTRICLE.’ Left ventricle contraction allows blood to flow from ‘AORTA’ ventricle tp. ‘SYSTOLE’ is defined as contraction time, and ‘DIASTOLE’ is a relaxation period. Per-minute the heart pumps out five liters of blood. 75 to 80% of the blood capacity is in the veins at any time and 20% in arteries and enduring in capillaries.

B) Premature Ventricle Contraction:

Cardiovascular disorders are regarded as one of the most severe disorders and leading causes of death worldwide. Premature ventricular contractions are among the greatest severe cardiac arrhythmias and been a concern for cardiologists. Ventricular tachycardia (VT) is an irregular heart rate which is strong. It begins in lower chambers of the heart, named as the ventricles.

Ventricle Contraction (VT) is definite as three or more heartbeats in time, at a rate of over 100 heartbeats per min. If Ventricle Contraction lasts additional than a couple of sec at a time, it may become dangerous. PVC signs include a sense of fluttering or flip-flop in the abdomen, speeding or hopping heart rate, skipping beats.PVCs occur when ventricular contractions beat faster than the anticipated next daily heartbeat, frequently interrupting the usual pumping order. A faster rhythm accompanies the extra beat, which produces the impression of a skipped beat or a flutter.

 Electrocardiogram

An electrocardiogram (ECG) can recognize the extra beats and the pattern and source.

Halter monitor.

The patient can carry this device on a belt or shoulder strap in their pocket or in a pouch. This also tracks the operation of the heart for 24 or 48 hours and gives the doctor an extended look at the heart rhythms of the patient.

Event recorder.

For home monitoring of the movement of our heart this system can be held in our pocket or worn on a belt or shoulder strap. We must press a button when we feel symptoms, and a brief recording of the ECG strip is made. The recorder which can be used for several weeks allows our doctor at the time of our symptoms to see our heart rhythm.

Exercise stress ECG.

The study uses electrocardiography to measure the electrical activity of our heart while walking on a treadmill or pedaling an exercise bike. This will assist in deciding whether exercise activates our PVCs.

One of the most popular, non-invasive methods; and the least expensive method for investigating heart disease is to record and interpret the signals from the electrocardiogram ( ECG). Many drugs, including decongestants, high blood pressure, alcohol, anemia, and tobacco use, maybe induced or activated by heart disease or scarring. Premature

Ventricle Contractions can be recognized for the reason that

(i)    They reach early

(ii)   The next beat arises at the normal time since it is created by the SA node and

(iii)  The QRS width is larger than 80m/sec

 Premature Ventricle Contraction (PVC) can be determined or confirmed in the following analysis

Figure 1Analysis of PVC

Figure 1 shows the premature ventricle contraction analysis. It consists of

i) PR COUNTER

It is an input of 4ms period clock. The counter status counting on first position. Pulse implies P steps on the next positive pulse(R) . The number of counter for 120ms = 30. Hence for 200 ms its 50.

Hence if the count is less than 30 or greater than 50, a bulb glows.

ii) QRS COUNTER:

Its triggers given an active low input. Its resistance negative pulse implies α, S. the counter starts at α and ends at S. the number of pulses for 4ms = 20. The bulb glows once the count increases.

CHECKING FOR PVC’S:

Figure 2 Checking PVC

            If we have a PVC complex of α’ R’ S’ along with αRS. We can first separate half the point less than 0.25 mv to get the peaks (positive) corresponding to negative α pulses at R’, R. We will take the positive pulses exceed one, then a bulb glows. The number of PVC’s called be from subtracting one from counters output

PEAK DETECTORS:

Wedetect the peak from a threshold value of 1 mv and obtain the   peak value from it and corresponding to R.