"How's the traffic?" That's one of the first questions I ask patients who visit my office. But I'm not just making small talk. Being stuck in traffic raises blood pressure and triples heart attack risk. So if a patient has had a tough commute and her BP is elevated, I'll recheck it later.

    There are other surprising situations and times when the chance of heart attack rises dramatically. If you or someone you know has a history of heart trouble, here's when to be watchful:

    First thing in the morning

    The risk of heart attack increases 40% in the morning, Harvard researchers estimate. Why? As you awaken, your body secretes adrenaline and other stress hormones, increasing blood pressure and a demand for oxygen. Your blood is also thicker and harder to pump because you're partially dehydrated. All this taxes the heart. Protect yourself: Build some time into your wake schedule so you can hit the snooze button and wake up slowly. If you're a morning exerciser, warm up thoroughly so as not to additionally stress the heart. And if you're on a beta-blocker, take it before bed so the medication is at full strength in the AM.

    On Monday mornings especially

    Twenty percent more heart attacks occur on this day, probably because people are stressed and depressed about returning to work. Protect yourself: Relax on Sunday, but try not to sleep in. Getting up early on Monday after sleeping late Saturday and Sunday can raise blood pressure even more because your body is fatigued and its natural rhythms are out of whack. Try to maintain a regular sleep/wake schedule all week.

    At the podium

    From the heart's perspective, public speaking can be similar to unaccustomed exercise. Extreme nervousness raises blood pressure, heart rate, and adrenaline levels, all of which can make the presentation itself a secondary worry. Protect yourself: To counter these effects, some of my patients take a betablocker before speaking, flying, or doing anything that makes them overly anxious.

    After a high-fat, high-carb meal

    Studies show these foods constrict blood vessels, making blood more prone to clot. Protect yourself: If you must indulge, keep your portion sizes reasonable. A daily aspirin will also help prevent blood "stickiness."

    During a bowel movement

    Straining increases pressure in the chest, slowing the return of blood to the heart. Protect yourself: Eat lots of fiber, stay hydrated, and avoid straining.

    During vigorous exercise you're unprepared for

    Having a heart attack while shoveling snow is a classic example of this. The heart attack occurs because the victim isn't accustomed to that kind of effort and stress hormones skyrocket, causing blood pressure and heart rate to jump. Protect yourself: Regular exercise protects your heart. But increase your intensity level gradually.

    交通状况怎样？"这是我向走进我办公室的患者首先问到的问题之一。我不仅仅是在闲聊。交通堵塞会使人血压升高，心脏病发作风险提高二倍。所以如果刚经历了交通堵塞，那么她的血压会升高，我会过一会再一次检查血压。

    还有一些处境和时间心脏病发作机率大幅升高。如果您或您认识的某个人有心脏病史，那么以下时间必须当心：

    早晨的第一件事

    哈佛研究人员估计，早晨心脏病发作的风险增加40%.原因何在？因为您刚苏醒，身体会分泌肾上腺素和其它应激激素，血压升高，氧需求量增大。因为您身体部分脱水所以血液较稠，心脏不易将其泵动。这些都加重了心脏的负担。自我保护措施：在您起床时间表中安排一些时间，这样您就可以按下闹铃按钮，慢慢苏醒。如果您是位晨练者，那么要充分热身，这样就不会给心脏增加另外的压力。再者，如果您正在服用β受体阻滞剂，那么请在睡前服用，这样药力在午夜时最强。

    星期一早晨特别当心

    百分之二十以上的心脏病在这一天发作，这也许是因为人们对于又要上班感到紧张和沮丧的缘故。自我保护：在星期天放松，但尽量不要睡过头。星期六和星期天晚睡之后星期一早起可使血压升得更高，因为您身体疲劳，生理节奏需要调整。整个一周都要保持有规律的睡眠-觉醒节律。

    站讲台

    从心脏的角度讲，公开演讲与不习惯的运动的作用相似。极度紧张使血压升高，心率加快，肾上腺素水平上升，所有这些可使演讲本身成为第二大让人担忧的事情。自我保护措施：为了对抗这些作用，我的有些病人在演讲、乘飞机或做任何使他们感到过分紧张的事情之前服用β受体阻滞剂

    高脂肪、高碳水化合物饮食之后

    研究表明，这些食物收缩血管，使血液更具凝结的倾向。自我保护措施：如果您必须吃这些食物，那么请您保持合适的量。每天服用阿司匹林也有助于防止血栓的形成。

    排便过程中

    过度用力会增加胸部压力，减慢血液流回心脏。自我保护措施：多吃含纤维的食物，保持大全湿润，避免过度用力。

    在进行没有准备的剧烈运动过程中

    患心脏病还铲雪就是典型例子。心脏病发作是因为患者对此类活动不适应，应激激素直线上升，引进血压和心率猛增。自我保护措施：经常锻炼会保护您的心脏，但锻炼强度应逐渐增加。