Anger and other strong emotions (情感) can probably cause deadly heart beats in certain weak people，the US researchers said on Monday.
Earlier studies have shown that earthquake，war or even the loss of a World Cup Soccer game can increase chances of death from sudden cardiac arrest，in which the heart stops passing blood.
“It’s certainly been shown in all different ways that when you put people under pressure，sudden death will increase，” said Dr.Rachel Lampert of Yale University in New Haven，Connecticut.
“Our study starts to look at how this really has an effect on the electrical system of the heart，” Lampert said.
She and her assistants studied 62 patients with heart disease and ICDs that can discover dangerous heart beats and send an electrical shock to bring a normal heart beat back.
Patients in the study took part in an exercise in which they told a recent angry period while Lampert’s team did a test called TWave Alternant that measures electrical instability(不稳定性) in the heart.
Lampert said the team on purpose asked questions to get people to experience the angry period again.“We found in the lab that yes，anger did increase this electrical instability in these patients，” she said.
Next，they followed patients for three years to see which patients later had a cardiac arrest and needed a shock from their ICDs.“The people who had the highest anger were 10 times more likely than everyone else to have cardiac arrest，” she said.
Lampert said the study suggests that anger can be deadly，at least for people who are already weak to this type of electrical disorder in the heart.
From the passage we know cardiac arrest refers to ________.

A．someone who will be caught if he does something wrong

B．some place where you can show all your feelings

C．some disease that can kill people instantly

D．something used by patients in hospital

The underlined word “this” in Paragraph 4 refers to “________”．

A．feelings of anger and pressure

B．games

C．feelings of happiness

D．hunger

What did Lampert use to measure electrical instability of patients’ heart?

A．ICD and TWave Alternant test.

B．ICD and Cardic arrest.

C．Cardiac arrest.

D．The passage doesn’t tell us.

The passage is mainly about ________.

A．new findings for heart disease

B．that anger really can kill a person

C．a new test of measuring heart blood

D．a study showing danger of heart beats