Nota untuk diri sendiri. Mungkin juga untuk member sekalian alam.: February 2015

GST : Wawancara Sinar TV

All About Heart Rate (Pulse)

What should you know about your heart rate?

Even if you’re not an athlete, knowledge about your heart rate can help you monitor your fitness level — and it might even help you spot developing health problems.

Your heart rate, or pulse, is the number of times your heart beats per minute. Normal heart rate varies from person to person. Knowing yours can be an important heart-health gauge.

“As you age, changes in the rate and regularity of your pulse can change and may signify a heart condition or other condition that needs to be addressed,” said Richard Stein, M.D., professor of medicine and cardiology at the New York University School of Medicine in New York City and a volunteer for the American Heart Association.

Where is it and what is a normal heart rate?

The best places to find your pulse are the:

wrists
inside of your elbow
side of your neck
top of the foot

To get the most accurate reading, put your finger over your pulse and count the number of beats in 60 seconds, Stein said.

Your resting heart rate is the heart pumping the lowest amount of blood you need because you’re not exercising. If you’re sitting or lying and you’re calm, relaxed and aren’t ill, your heart rate is normally between 60 (beats per minute) and 100 (beats per minute), Stein said.

But a heart rate lower than 60 doesn’t usually signal a medical problem. It could be the result of taking a drug such as a beta blocker. A lower heart rate is also common for people who get a lot of physical activity or are very athletic, Stein said. Active people often have lower heart rates because their heart muscle is in better condition and doesn’t need to work as hard to maintain a steady beat.

“Moderate physical activity doesn’t usually change the resting pulse much,” Stein said. “If you’re very fit, it could change to 40. A less active person might have a heart rate between 60 and 100,” he added. That’s because the heart muscle has to work harder to maintain bodily functions, making it higher.

How Other Factors Affect Heart Rate

Air temperature: When temperatures (and the humidity) soar, the heart pumps a little more blood, so your pulse rate may increase, but usually no more than five to 10 beats a minute.

Body position: Resting, sitting or standing, your pulse is usually the same. Sometimes as you stand for the first 15 to 20 seconds, your pulse may go up a little bit, but after a couple of minutes it should settle down. Emotions: If you’re stressed, anxious or “extraordinarily happy or sad” your emotions can raise your pulse.

Body size: Body size usually doesn’t usually change pulse. If you’re very obese, you might see a higher resting pulse than normal, but usually not more than 100.

Medication use: Meds that block your adrenaline (beta blockers) tend to slow your pulse, while too much thyroid medication or too high of a dosage will raise it.

When To Call Your Doctor

If you’re on a beta blocker to decrease your heart rate (and lower blood pressure) or to control a another common abnormal rhythm (arrhythmia), your doctor may ask you to monitor and log your heart rate. Keeping tabs on your heart rate can help your doctor determine whether to change the dosage or switch to a different medication.

“If your pulse is very low or if you have frequent episodes of unexplained fast heart rates, especially if they cause you to feel weak or dizzy or faint, tell your doctor, who can decide if it’s an emergency,” Stein said. “Your pulse is one tool to help get a picture of your health.”

TYRES : How can I tell when my tyres need changing?

One sign that your tyres need changing is noticing a deterioration in performance. For example, your car does not handle or grip the road as well in poor weather conditions as it normally does, or it takes longer to stop when you apply the brakes.

The fact that tyres wear gradually can make it difficult to identify the reduction in performance, so it's best to have them checked regularly and preferably by an expert. It is the driver's responsibility to ensure that the tread on your tyres is not worn beyond the legal minimum limit of 1.6 millimetres.

To make this easier to identify, tyre manufacturers mould tread wear indicators (T.W.I) into the design of the tyres tread pattern usually at a tread level of 1.6mm. As soon as the tread is worn to the height of the tread wear indicator, the tyre has reached the legal minimum tread depth and you should replace the tyre as soon as possible.

You should also be aware that there are many different reasons for tyre wear. Your tyres don't just get worn through age and use, but through emergency braking, under-inflation or over-inflation. And if your wheels are misaligned, one edge of the tyre can wear more rapidly than the other edge.

Illustrations and explanation for tyre wear

	Under Inflation Under-inflation has caused this tyre to wear on the outer edges of the tread, leaving the central tread area far less worn. The tyre inner-liner can also degrade.
	Over Inflation Over-inflation has resulted in the central tread area being forced into contact with the road causing rapid or crown wear.
	Mis-Alignment A typical example of the wear pattern caused by front wheel misalignment, (Toe-in or toe-out). The edge of the tread is "feathered" and worn progressively from one side.
	Camber Wear Excessive wheel camber has caused sloping wear on the outer edge of the tread on one shoulder of this tyre.
	Illegal Wear This tyre has been used well after reaching the legal minimum pattern depth of 1.6mm across the central ¾ of the tread, going around the complete circumference of the tyre.
	End Of Life This tyre has reached the legal minimum pattern depth of 1.6mm.
	Emergency Braking An emergency braking manoeuvre with this tyre has caused the tyre to rapidly wear through the complete casing causing the tyre to deflate.
	Cuts Sharp objects can cause considerable damage rendering a tyre unserviceable.
	Impact Damage This is damage caused by an impact to the sidewall. The bulge or "egg" indicates localised casing damage.

TYRES : Load Index and Speed Ratings

The majority of tyres carry coded markings on them, which correspond to their load carrying and maximum speed capabilities.

For example: 91V

91= Index of maximum load carrying capacity per tyre, in this case equates to 615kg.

V= Symbol which equates to a speed rating of 240km/h (approximately 149mph)

The load index is a numerical code, which corresponds to the maximum load a tyre can carry at the speed indicated by its speed symbol, under specific service conditions. For specific load index details see below.

Load Index	Kilograms	Load Index	Kilograms	Load Index	Kilograms
65	290	80	450	95	690
66	300	81	462	96	710
67	307	82	475	97	730
68	315	83	487	98	750
69	325	84	500	99	775
70	335	85	515	100	800
71	345	86	530	101	825
72	355	87	545	102	850
73	365	88	560	103	875
74	375	89	580	104	900
75	387	90	600	105	925
76	400	91	615	106	950
77	412	92	630	107	975
78	425	93	650	108	1000
79	437	94	670

The speed symbol indicates the speed at which the tyre can carry the load corresponding with its load index. For specific speed rating details see below.

Speed Symbol	Approx MPH	Approx KM/H
Q	99	160
R	106	170
S	112	180
T	118	190
H	131	210
V	149	240
VR	131	210
W	168	270
Y	186	300
ZR	149	240

TYRES :What does the writing on my tyres mean?

There are two main purposes of the writing that you'll see on the sidewall of your tyres.

The first is to help identify the size and specification of the tyres correctly. The second is to confirm that the tyre has been tested and approved to European and other country safety standards. The European mandatory is known as 'E' marking.

Although not illegal, it is not recommended to have tyres with a lower speed rating or load capacity than the manufacturer recommended tyre specification for your vehicle, or to have a combination of different tyre construction types. Consult your vehicle handbook, which will confirm your vehicles tyre speed and load ratings as well as any additional requirements.

What does the writing on my tyres mean?