PAC  （心房早搏）、 PVC（过早心室收缩、室性心动过速）、

SVT（室上性心动过速）、VT(室性心动过速)、a.fib（心房颤动）

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Premature atrial contractions (PACs) are extra heartbeats that start in the upper chambers of your heart. When the premature, or early, signal tells the heart to contract, there may not be much blood in the heart at that moment. That means there's not much blood to pump out.

Premature ventricular contractions (PVCs) can cause a variety of symptoms, but many people don't notice them at all: 

• Chest sensations: A fluttering, flip-flop, or pounding feeling in the chest 
• Heartbeat sensations: A skipped, extra, or missed beat, or an increased awareness of your heartbeat 
• Other sensations: Dizziness, fatigue, or difficulty breathing
• 过早心室收缩 (PVC) 可引起多种症状，但许多人根本没有注意到它们：
• 胸部感觉：胸部颤动、扑通扑通或砰砰直跳的感觉
• 心跳感觉：心跳漏跳、多跳或漏掉，或对心跳的意识增强
• 其他感觉：头晕、疲劳或呼吸困难
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• Symptoms of PVCs include a fluttering or flip-flop feeling in the chest, pounding or jumping heart rate, skipped beats and palpitations, or an increased awareness of your heartbeat.
• 室性心动过速 (PVC) 的症状包括胸部颤动或扑腾感、心跳加速或心跳过快、心跳漏跳或心悸，或对心跳的意识增强。
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• Ventricular tachycardia (VT), also known as V-tach, is a type of abnormal heart rhythm, or arrhythmia, that occurs when the lower chambers of the heart beat too fast. It's defined as a pulse rate of more than 100 beats per minute with at least three irregular heartbeats in a row. VT can be harmless if it lasts only a few beats, but if it continues and is untreated, it can be life-threatening and cause sudden cardiac death. 室性心动过速 (VT)，也称为 V-tach，是一种异常心律或心律失常，发生在心脏下腔跳动过快时。其定义为脉搏率超过每分钟 100 次，且连续至少出现三次不规则心跳。如果 VT 仅持续几次，则无害，但如果持续且未经治疗，则可能危及生命并导致心源性猝死。
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Supraventricular tachycardia (SVT) is a heart condition that causes an abnormally fast heartbeat. It's a type of arrhythmia, or irregular heartbeat, that happens when the heart's electrical system malfunctions. This can cause the heart to beat too early in the upper chambers, which speeds up the heart rate. A normal resting heart rate is 60–100 beats per minute (bpm), but SVT can cause the heart rate to suddenly increase above 100 bpm, sometimes as high as 300 bpm. SVT can occur at any age, but often first appears in children or young adults. It can happen while resting or exercising, and episodes can start and stop very suddenly, lasting from minutes to hours. 室上性心动过速 (SVT) 是一种导致心跳异常加快的心脏病。这是一种心律失常或心律不齐，发生在心脏电气系统发生故障时。这会导致心脏上腔过早跳动，从而加快心率。正常的静息心率为每分钟 60-100 次 (bpm)，但 SVT 会导致心率突然增加到 100 bpm 以上，有时甚至高达 300 bpm。SVT 可能发生在任何年龄，但通常首先出现在儿童或年轻人身上。它可能在休息或运动时发生，并且发作可能非常突然地开始和停止，持续时间从几分钟到几小时不等。

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Atrial fibrillation (AFib) is a heart condition that causes the upper chambers of the heart to beat irregularly and rapidly, sometimes as fast as 500–600 beats per minute. This irregular heartbeat, also known as an arrhythmia, can cause blood to flow poorly from the atria to the ventricles. AFib can occur in brief episodes or be a permanent condition. 

心房颤动 (AFib) 是一种心脏病，会导致心脏上腔跳动不规律且快速，有时每分钟跳动速度高达 500-600 次。这种不规律的心跳也称为心律失常，会导致血液从心房流向心室不畅。AFib 可能短暂发作，也可能成为永久性疾病。