Pericardial effusions typically lead to low QRS voltages or electrical alternans, and can be seen on an echocardiograph.

心包积液常显示QRS低电压或电交替象；超声心动图也可做出诊断。

First, if the AV node is receptive, it gets conducted down to the ventricles, resulting in a normal QRS complex.

首先，如果房室结接受它，它将向下传导到心室，形成一个正常的QRS。

People with WPW usually have a PR interval less than 120 ms, and a QRS complex greater than 110 ms.

WPW患者的PR间期常常小于120ms，QRS大于110ms。

Now - in both these situations, the QRS complex comes in early, which means an early ventricular contraction.

，这两种情况下，QRS群都会提前出，意味着一次提前的心室收缩。

This is known as a " blocked" P wave or a " dropped" QRS complex.

这就是所谓的P“被阻滞”或QRS群“脱落”。

The ventricular contraction is seen as a QRS complex, and the ventricular repolarization, and therefore it's relaxation, is seen as a T-wave.

心室收缩以QRS群的形式展，心室极以及因此发生舒张的形，则视为T。

Also, the ST segment and T wave, which represent repolarization, will often be directed opposite the QRS complex.

同时，代表极的ST段和T通常与QRS主方向相反。

In this example, there are four P waves for every three QRS complexes.

这个例子中，每3个QRS有4个P。

You just had 5 mLs. House: The QRS is getting wider.

护士: 你刚刚吸了5毫升。豪斯: QRS越来越宽了。

Thus, the QRS complex starts as predominantly negative in V1, and ends as predominantly positive in V6.

因此，QRS群V1开始时主要为负，V6时以正性结束。

The number of QRS complexes always equals the number of P waves MINUS one.

QRS的数目总是等于P数目-1。

In severe cases, it can also cause a prolonged PR interval, a diminished or absent P wave, and a widened QRS complex.

情况严重时，甚至可以出PR间期延长、P消失以及QRS变宽。

Absence of P waves and presence of irregular narrow QRS complexes are the hallmark of atrial fibrillation.

无P和不规则窄QRS是心房颤动的特征。

In this situation, the depolarization wave conducts down the left bundle branch and then through the ventricles aberrantly, resulting in an abnormally wide QRS complex.

这种情况下，除极向下传导到左束支，然后异常地穿过心室，导致一个异常增宽的QRS群。

On an ECG, atrial fibrillation is characterized by absence of P-waves and irregular narrow QRS complexes.

ECG上，心房颤动的特征是没有P和不规则的窄QRS群。

On an ECG, this is seen as PROGRESSIVE prolongation of PR interval followed by a P wave WITHOUT a QRS complex.

心电图上，可见PR间期渐进性延长，随后是P，无QRS。

Also, you might have multiple ectopic foci PVCs, producing different appearing QRS complexes on a single rhythm strip.

同样，你可能有许多室性期前收缩的异位起搏点，单一的心律带上产生了不同形式的QRS群。

The QRS complex represents depolarization of the ventricles which starts with the interventricular septum.

QRS群代表心室从室间隔开始的去极化。

The number of flutter waves preceding a QRS complex corresponds to number of atrial contractions to one ventricular contraction.

一个QRS群前的房扑的数目，相当于一次心室收缩对应的心房收缩的数目。

Alright, so let's say this heart's cruising along at about 60 bpm, which means that there's 1 second between p waves and QRS complexes.

让我们假设这个心脏正以60次/分的心率循环搏动，这表示P和QRS之间有1秒钟。